1.6.0

Local preview

• mkdocs serve no longer locks up the browser when more than 5 tabs are open. This is achieved by closing the polling connection whenever a tab becomes inactive. Background tabs will no longer auto-reload either - that will instead happen as soon the tab is opened again. Context: #3391

• New flag serve --open to open the site in a browser.
  After the first build is finished, this flag will cause the default OS Web browser to be opened at the home page of the local site.
  Context: #3500

Drafts

Warning

Changed from version 1.5:

The exclude_docs config was split up into two separate concepts.

The exclude_docs config no longer has any special behavior for mkdocs serve - it now always completely excludes the listed documents from the site.

If you wish to use the "drafts" functionality like the exclude_docs key used to do in MkDocs 1.5, please switch to the new config key draft_docs.

See documentation.

Other changes:

• Reduce warning levels when a "draft" page has a link to a non-existent file. Context: #3449

Update to deduction of page titles

MkDocs 1.5 had a change in behavior in deducing the page titles from the first heading. Unfortunately this could cause unescaped HTML tags or entities to appear in edge cases.

Now tags are always fully sanitized from the title. Though it still remains the case that Page.title is expected to contain HTML entities and is passed directly to the themes.

Images (notably, emojis in some extensions) get preserved in the title only through their alt attribute's value.

Context: #3564, #3578

Themes

• Built-in themes now also support Polish language (#3613)

"readthedocs" theme

• Fix: "readthedocs" theme can now correctly handle deeply nested nav configurations (over 2 levels deep), without confusedly expanding all sections and jumping around vertically. (#3464)

• Fix: "readthedocs" theme now shows a link to the repository (with a generic logo) even when isn't one of the 3 known hosters. (#3435)

• "readthedocs" theme now also has translation for the word "theme" in the footer that mistakenly always remained in English. (#3613, #3625)

"mkdocs" theme

The "mkdocs" theme got a big update to a newer version of Bootstrap, meaning a slight overhaul of styles. Colors (most notably of admonitions) have much better contrast.

The "mkdocs" theme now has support for dark mode - both automatic (based on the OS/browser setting) and with a manual toggle. Both of these options are not enabled by default and need to be configured explicitly.
See color_mode, user_color_mode_toggle in documentation.

Warning

Possible breaking change:

jQuery is no longer included into the "mkdocs" theme. If you were relying on it in your scripts, you will need to separately add it first (into mkdocs.yml) as an extra script:

extra_javascript:
  - https://code.jquery.com/jquery-3.7.1.min.js

Or even better if the script file is copied and included from your docs dir.

Context: #3493, #3649

Configuration

New "enabled" setting for all plugins

You may have seen some plugins take up the convention of having a setting enabled: false (or usually controlled through an environment variable) to make the plugin do nothing.

Now every plugin has this setting. Plugins can still choose to implement this config themselves and decide how it behaves (and unless they drop older versions of MkDocs, they still should for now), but now there's always a fallback for every plugin.

See documentation. Context: #3395

Validation

Validation of hyperlinks between pages

Absolute links

Historically, within Markdown, MkDocs only recognized relative links that lead to another physical *.md document (or media file). This is a good convention to follow because then the source pages are also freely browsable without MkDocs, for example on GitHub. Whereas absolute links were left unmodified (making them often not work as expected or, more recently, warned against).

If you dislike having to always use relative links, now you can opt into absolute links and have them work correctly.

If you set the setting validation.links.absolute_links to the new value relative_to_docs, all Markdown links starting with / will be understood as being relative to the docs_dir root. The links will then be validated for correctness according to all the other rules that were already working for relative links in prior versions of MkDocs. For the HTML output, these links will still be turned relative so that the site still works reliably.

So, now any document (e.g. "dir1/foo.md") can link to the document "dir2/bar.md" as [link](/dir2/bar.md), in addition to the previously only correct way [link](../dir2/bar.md).

You have to enable the setting, though. The default is still to just skip any processing of such links.

See documentation. Context: #3485

Absolute links within nav

Absolute links within the nav: config were also always skipped. It is now possible to also validate them in the same way with validation.nav.absolute_links. Though it makes a bit less sense because then the syntax is simply redundant with the syntax that comes without the leading slash.

Anchors

There is a new config setting that is recommended to enable warnings for:

validation:
  anchors: warn

Example of a warning that this can produce:

WARNING -  Doc file 'foo/example.md' contains a link '../bar.md#some-heading', but the doc 'foo/bar.md' does not contain an anchor '#some-heading'.

Any of the below methods of declaring an anchor will be detected by MkDocs:

## Heading producing an anchor

## Another heading {#custom-anchor-for-heading-using-attr-list}

<a id="raw-anchor"></a>

[](){#markdown-anchor-using-attr-list}

Plugins and extensions that insert anchors, in order to be compatible with this, need to be developed as treeprocessors that insert etree elements as their mode of operation, rather than raw HTML which is undetectable for this purpose.

If you as a user are dealing with falsely reported missing anchors and there's no way to resolve this, you can choose to disable these messages by setting this option to ignore (and they are at INFO level by default anyway).

See documentation. Context: #3463

Other changes:

• When the nav config is not specified at all, the not_in_nav setting (originally added in 1.5.0) gains an additional behavior: documents covered by not_in_nav will not be part of the automatically deduced navigation. Context: #3443

• Fix: the !relative YAML tag for markdown_extensions (originally added in 1.5.0) - it was broken in many typical use cases.

  See documentation. Context: #3466

• Config validation now exits on first error, to avoid showing bizarre secondary errors. Context: #3437

• MkDocs used to shorten error messages for unexpected errors such as "file not found", but that is no longer the case, the full error message and stack trace will be possible to see (unless the error has a proper handler, of course). Context: #3445

Upgrades for plugin developers

Plugins can add multiple handlers for the same event type, at multiple priorities

See mkdocs.plugins.CombinedEvent in documentation. Context: #3448

Enabling true generated files and expanding the File API

See documentation.

• There is a new pair of attributes File.content_string that becomes the official API for obtaining the content of a file and is used by MkDocs itself.

  This replaces the old approach where one had to manually read the file located at File.abs_src_path, although that is still the primary action that these new attributes do under the hood.

• The content of a File can be backed by a string and no longer has to be a real existing file at abs_src_path.

  It is possible to set the attribute File.content_string or File.content_bytes and it will take precedence over abs_src_path.

  Further, abs_src_path is no longer guaranteed to be present and can be None instead. MkDocs itself still uses physical files in all cases, but eventually plugins will appear that don't populate this attribute.

• There is a new constructor File.generated() that should be used by plugins instead of the File() constructor. It is much more convenient because one doesn't need to manually look up the values such as docs_dir and use_directory_urls. Its signature is one of:

  f = File.generated(config: MkDocsConfig, src_uri: str, content: str | bytes)
  f = File.generated(config: MkD...

1.5.3

• Fix mkdocs serve sometimes locking up all browser tabs when navigating quickly (#3390)

• Add many new supported languages for "search" plugin - update lunr-languages to 1.12.0 (#3334)

• Bugfix (regression in 1.5.0): In "readthedocs" theme the styling of "breadcrumb navigation" was broken for nested pages (#3383)

• Built-in themes now also support Chinese (Traditional, Taiwan) language (#3370)

• Plugins can now set File.page to their own subclass of Page. There is also now a warning if File.page is set to anything other than a strict subclass of Page. (#3367, #3381)

  Note that just instantiating a Page sets the file automatically, so care needs to be taken not to create an unneeded Page.

Other small improvements; see commit log.

1.5.2

• Bugfix (regression in 1.5.0): Restore functionality of --no-livereload. (#3320)

• Bugfix (regression in 1.5.0): The new page title detection would sometimes be unable to drop anchorlinks - fix that. (#3325)

• Partly bring back pre-1.5 API: extra_javascript items will once again be mostly strings, and only sometimes ExtraStringValue (when the extra script functionality is used).

  Plugins should be free to append strings to config.extra_javascript, but when reading the values, they must still make sure to read it as str(value) in case it is an ExtraScriptValue item. For querying the attributes such as .type you need to check isinstance first. Static type checking will guide you in that. (#3324)

See commit log.

1.5.1

• Bugfix (regression in 1.5.0): Make it possible to treat ExtraScriptValue as a path. This lets some plugins still work despite the breaking change.

• Bugfix (regression in 1.5.0): Prevent errors for special setups that have 3 conflicting files, such as index.html, index.md and README.md (#3314)

See commit log.

1.5.0

New: MkDocs now accepts donations. Please consider supporting the current maintainer at my new GitHub sponsorship page.

MkDocs has been a totally free project since the beginning and wasn't accepting funds. MkDocs will remain free of paywalls, but now you can show your support with donations (one-time and/or recurring).

Donate for MkDocs - @oprypin sponsors page

And please also consider these other individuals who have been contributing to the ecosystem for a long time and check out their donations pages:

@facelessuser
@pawamoy
@Ultrabug

---

Release 1.5.0

New command mkdocs get-deps

This command guesses the Python dependencies that a MkDocs site requires in order to build. It simply prints the PyPI packages that need to be installed. In the terminal it can be combined directly with an installation command as follows:

pip install $(mkdocs get-deps)

The idea is that right after running this command, you can directly follow it up with mkdocs build and it will almost always "just work", without needing to think which dependencies to install.

The way it works is by scanning mkdocs.yml for themes:, plugins:, markdown_extensions: items and doing a reverse lookup based on a large list of known projects (catalog, see below).

Of course, you're welcome to use a "virtualenv" with such a command. Also note that for environments that require stability (for example CI) directly installing deps in this way is not a very reliable approach as it precludes dependency pinning.

The command allows overriding which config file is used (instead of mkdocs.yml in the current directory) as well as which catalog of projects is used (instead of downloading it from the default location). See mkdocs get-deps --help.

Context: #3205

MkDocs has an official catalog of plugins

Check out https://github.com/mkdocs/catalog and add all your general-purpose plugins, themes and extensions there, so that they can be looked up through mkdocs get-deps.

This was renamed from "best-of-mkdocs" and received significant updates. In addition to pip installation commands, the page now shows the config boilerplate needed to add a plugin.

Expanded validation of links

Validated links in Markdown

As you may know, within Markdown, MkDocs really only recognizes relative links that lead to another physical *.md document (or media file). This is a good convention to follow because then the source pages are also freely browsable without MkDocs, for example on GitHub. MkDocs knows that in the output it should turn those *.md links into *.html as appropriate, and it would also always tell you if such a link doesn't actually lead to an existing file.

However, the checks for links were really loose and had many concessions. For example, links that started with / ("absolute") and links that ended with / were left as is and no warning was shown, which allowed such very fragile links to sneak into site sources: links that happen to work right now but get no validation and links that confusingly need an extra level of .. with use_directory_urls enabled.

Now, in addition to validating relative links, MkDocs will print INFO messages for unrecognized types of links (including absolute links). They look like this:

INFO - Doc file 'example.md' contains an absolute link '/foo/bar/', it was left as is. Did you mean 'foo/bar.md'?

If you don't want any changes, not even the INFO messages, and wish to revert to the silence from MkDocs 1.4, add the following configs to mkdocs.yml (not recommended):

validation:
  absolute_links: ignore
  unrecognized_links: ignore

If, on the opposite end, you want these to print WARNING messages and cause mkdocs build --strict to fail, you are recommended to configure these to warn instead.

See documentation for actual recommended settings and more details. Context: #3283

Validated links in the nav

Links to documents in the nav configuration now also have configurable validation, though with no changes to the defaults.

You are welcomed to turn on validation for files that were forgotten and excluded from the nav. Example:

validation:
  nav:
    omitted_files: warn
    absolute_links: warn

This can make the following message appear with the WARNING level (as opposed to INFO as the only option previously), thus being caught by mkdocs --strict:

INFO - The following pages exist in the docs directory, but are not included in the "nav" configuration: ...

See documentation. Context: #3283, #1755

Mark docs as intentionally "not in nav"

There is a new config not_in_nav. With it, you can mark particular patterns of files as exempt from the above omitted_files warning type; no messages will be printed for them anymore. (As a corollary, setting this config to * is the same as ignoring omitted_files altogether.)

This is useful if you generally like these warnings about files that were forgotten from the nav, but still have some pages that you knowingly excluded from the nav and just want to build and copy them.

The not_in_nav config is a set of gitignore-like patterns. See the next section for an explanation of another such config.

See documentation. Context: #3224, #1888

Excluded doc files

There is a new config exclude_docs that tells MkDocs to ignore certain files under docs_dir and not copy them to the built site as part of the build.

Historically MkDocs would always ignore file names starting with a dot, and that's all. Now this is all configurable: you can un-ignore these and/or ignore more patterns of files.

The exclude_docs config follows the .gitignore pattern format and is specified as a multiline YAML string. For example:

exclude_docs: |
  *.py               # Excludes e.g. docs/hooks/foo.py
  /drafts            # Excludes e.g. docs/drafts/hello.md
  /requirements.txt  # Excludes docs/requirements.txt

Validation of links (described above) is also affected by exclude_docs. During mkdocs serve the messages explain the interaction, whereas during mkdocs build excluded files are as good as nonexistent.

As an additional related change, if you have a need to have both README.md and index.md files in a directory but publish only one of them, you can now use this feature to explicitly ignore one of them and avoid warnings.

See documentation. Context: #3224

Drafts

The exclude_docs config has another behavior: all excluded Markdown pages will still be previewable in mkdocs serve only, just with a "DRAFT" marker on top. Then they will of course be excluded from mkdocs build or gh-deploy.

If you don't want mkdocs serve to have any special behaviors and instead want it to perform completely normal builds, use the new flag mkdocs serve --clean.

See documentation. Context: #3224

mkdocs serve no longer exits after build errors

If there was an error (from the config or a plugin) during a site re-build, mkdocs serve used to exit after printing a stack trace. Now it will simply freeze the server until the author edits the files to fix the problem, and then will keep reloading.

But errors on the first build still cause mkdocs serve to exit, as before.

Context: #3255

Page titles will be deduced from any style of heading

MkDocs always had the ability to infer the title of a page (if it's not specified in the nav) based on the first line of the document, if it had a <h1> heading that had to written starting with the exact character #. Now any style of Markdown heading is understood (#1886). Due to the previous simplistic parsing, it was also impossible to use attr_list attributes in that first heading (#3136). Now that is also fixed.

Markdown extensions can use paths relative to the current document

This is aimed at extensions such as pymdownx.snippets or markdown_include.include: you can now specify their include paths to be relative to the currently rendered Markdown document, or relative to the docs_dir. Any other extension can of course also make use of the new !relative YAML tag.

markdown_extensions:
  - pymdownx.snippets:
      base_path: !relative

See documentation. Context: #2154, #3258

<script> tags can specify type="module" and other attributes

In extra_javascript, if you use the .mjs file extension or explicitly specify a type: module key, the script will be added with the type="module" attribute. defer: true and async: true keys are also available.

See updated documentation for extra_javascript.

At first this is only supported in built-in themes, other themes need to follow up, see below.

Context: #3237

Changes for theme developers (action required!)

Using the construct {% for script in extra_javascript %} is now fully obsolete because it cannot allow customizing the attributes of the <script> tag. It will keep working b...

1.4.3

• Bugfix: for the hooks feature, modules no longer fail to load if using some advanced Python features like dataclasses (#3193)

• Bugfix: Don't create None sitemap entries if the page has no populated URL - affects sites that exclude some files from navigation (07a297b)

• "readthedocs" theme:

  • Accessibility: add aria labels to Home logo (#3129) and search inputs (#3046)
  • "readthedocs" theme now supports hljs_style: config, same as "mkdocs" theme (#3199)

• Translations:

  • Built-in themes now also support Indonesian language (#3154)
  • Fixed zh_CN translation (#3125)
  • tr_TR translation becomes just tr - usage should remain unaffected (#3195)

See commit log.

1.4.2

• Officially support Python 3.11 (#3020)

  Note: Simply upgrading to Python 3.11 can cut off 10-15% of your site's build time.

• Support multiple instances of the same plugin (#3027)

  If a plugin is specified multiple times in the list under the plugins: config, that will create 2 (or more) instances of the plugin with their own config each.

  Previously this case was unforeseen and, as such, bugged.

  Now even though this works, by default a warning will appear from MkDocs anyway, unless the plugin adds a class variable supports_multiple_instances = True.

• Bugfix (regression in 1.4.1): Don't error when a plugin puts a plain string into warnings (#3016)

• Bugfix: Relative links will always render with a trailing slash (#3022)

  Previously under use_directory_urls, links from a sub-page to the main index page rendered as e.g. <a href="../.."> even though in all other cases the links look like <a href="../../">. This caused unwanted behavior on some combinations of Web browsers and servers. Now this special-case bug was removed.

• Built-in "mkdocs" theme now also supports Norwegian language (#3024)

• Plugin-related warnings look more readable (#3016)

See commit log.

1.4.1

• Support theme-namespaced plugin loading (#2998)

  Plugins' entry points can be named as 'sometheme/someplugin'. That will have the following outcome:

  • If the current theme is 'sometheme', the plugin 'sometheme/someplugin' will always be preferred over 'someplugin'.
  • If the current theme isn't 'sometheme', the only way to use this plugin is by specifying plugins: [sometheme/someplugin].

  One can also specify plugins: ['/someplugin'] instead of plugins: ['someplugin'] to definitely avoid the theme-namespaced plugin.

• Bugfix: mkdocs serve will work correctly with non-ASCII paths and redirects (#3001)

• Windows: 'colorama' is now a dependency of MkDocs, to ensure colorful log output (#2987)

• Plugin-related config options have more reliable validation and error reporting (#2997)

• Translation sub-commands of setup.py were completely dropped. See documentation [1] [2] for their new replacements (#2990)

• The 'mkdocs' package (wheel and source) is now produced by Hatch build system and pyproject.toml instead of setup.py (#2988)

Other small improvements; see commit log.

1.4.0

Feature upgrades

Hooks (#2978)

The new hooks: config allows you to add plugin-like event handlers from local Python files, without needing to set up and install an actual plugin.

See documentation.

edit_uri flexibility (#2927)

There is a new edit_uri_template: config.
It works like edit_uri but more generally covers ways to construct an edit URL.
See documentation.

Additionally, the edit_uri functionality will now fully work even if repo_url is omitted (#2928)

Upgrades for plugin developers

Note: this release has big changes to the implementation of plugins and their configs. But, the intention is to have zero breaking changes in all reasonably common use cases. Or at the very least if a code fix is required, there should always be a way to stay compatible with older MkDocs versions. Please report if this release breaks something.

Customize event order for plugin event handlers (#2973)

Plugins can now choose to set a priority value for their event handlers. This can override the old behavior where for each event type, the handlers are called in the order that their plugins appear in the plugins config.

If this is set, events with higher priority are called first. Events without a chosen priority get a default of 0. Events that have the same priority are ordered as they appear in the config.

Recommended priority values: 100 "first", 50 "early", 0 "default", -50 "late", -100 "last".
As different plugins discover more precise relations to each other, the values should be further tweaked.

See documentation.

New events that persist across builds in mkdocs serve (#2972)

The new events are on_startup and on_shutdown. They run at the very beginning and very end of an mkdocs invocation.
on_startup also receives information on how mkdocs was invoked (e.g. serve --dirtyreload).

See documentation.

Replace File.src_path to not deal with backslashes (#2930)

The property src_path uses backslashes on Windows, which doesn't make sense as it's a virtual path.
To not make a breaking change, there's no change to how this property is used, but now you should:

• Use File.src_uri instead of File.src_path
• and File.dest_uri instead of File.dest_path.

These consistently use forward slashes, and are now the definitive source that MkDocs itself uses.

See source code.

As a related tip: you should also stop using os.path.* or pathlib.Path() to deal with these paths, and instead use posixpath.* or pathlib.PurePosixPath()

MkDocs is type-annotated, ready for use with mypy (#2941, #2970)

Type annotations for event handler methods (#2931)

MkDocs' plugin event methods now have type annotations. You might have been adding annotations to events already, but now they will be validated to match the original.

See source code and documentation.

One big update is that now you should annotate method parameters more specifically as config: defaults.MkDocsConfig instead of config: base.Config. This not only makes it clear that it is the main config of MkDocs itself, but also provides type-safe access through attributes of the object (see next section).

See source code and documentation.

Rework ConfigOption schemas as class-based (#2962)

When developing a plugin, the settings that it accepts used to be specified in the config_scheme variable on the plugin class.
This approach is now soft-deprecated, and instead you should specify the config in a sub-class of base.Config.

Old example:

from mkdocs import plugins
from mkdocs.config import base, config_options

class MyPlugin(plugins.BasePlugin):
    config_scheme = (
        ('foo', config_options.Type(int)),
        ('bar', config_options.Type(str, default='')),
    )

    def on_page_markdown(self, markdown: str, *, config: base.Config, **kwargs):
        if self.config['foo'] < 5:
            if config['site_url'].startswith('http:'):
                return markdown + self.config['baz']

This code snippet actually has many mistakes but it will pass all type checks and silently run and even succeed in some cases.

So, on to the new equivalent example, changed to new-style schema and attribute-based access:
(Complaints from "mypy" added inline)

from mkdocs import plugins
from mkdocs.config import base, config_options as c

class MyPluginConfig(base.Config):
    foo = c.Optional(c.Type(int))
    bar = c.Type(str, default='')

class MyPlugin(plugins.BasePlugin[MyPluginConfig]):
    def on_page_markdown(self, markdown: str, *, config: base.MkDocsConfig, **kwargs):
        if self.config.foo < 5:  # Error, `foo` might be `None`, need to check first.
            if config.site_url.startswith('http:'):  # Error, MkDocs' `site_url` also might be `None`.
                return markdown + self.config.baz  # Error, no such attribute `baz`!

This lets you notice the errors from a static type checker before running the code and fix them as such:

class MyPlugin(plugins.BasePlugin[MyPluginConfig]):
    def on_page_markdown(self, markdown: str, *, config: base.MkDocsConfig, **kwargs):
        if self.config.foo is not None and self.config.foo < 5:  # OK, `int < int` is valid.
            if (config.site_url or '').startswith('http:'):  # OK, `str.startswith(str)` is valid.
                return markdown + self.config.bar  # OK, `str + str` is valid.

See documentation.

Also notice that we had to explicitly mark the config attribute foo as Optional.
The new-style config has all attributes marked as required by default, and specifying required=False or required=True is not allowed!

New: config_options.Optional (#2962)

Wrapping something into Optional is conceptually similar to "I want the default to be None" -- and you have to express it like that, because writing default=None doesn't actually work.

Breaking change: the method BaseConfigOption.is_required() was removed. Use .required instead. (#2938)
And even the required property should be mostly unused now.
For class-based configs, there's a new definition for whether an option is "required":

• It has no default, and
• It is not wrapped into config_options.Optional.

New: config_options.ListOfItems (#2938)

Defines a list of items that each must adhere to the same constraint. Kind of like a validated Type(list)

Examples how to express a list of integers (with from mkdocs.config import config_options as c):

Description	Code entry
Required to specify	foo = c.ListOfItems(c.Type(int))
Optional, default is []	foo = c.ListOfItems(c.Type(int), default=[])
Optional, default is None	foo = c.Optional(c.ListOfItems(c.Type(int)))

See more examples in documentation.

Updated: config_options.SubConfig (#2807)

SubConfig used to silently ignore all validation of its config options. Now you should pass validate=True to it or just use new class-based configs where this became the default.

So, it can be used to validate a nested sub-dict with all keys pre-defined and value types strictly validated.

See examples in documentation.

Other changes to config options

URL's default is now None instead of ''. This can still be checked for truthiness in the same way - if config.some_url: (#2962)

FilesystemObject is no longer abstract and can be used directly, standing for "file or directory" with optional existence checking (#2938)

Bug fixes:

• Fix SubConfig, ConfigItems, MarkdownExtensions to not leak values across different instances (#2916, #2290)
• SubConfig raises the correct kind of validation error without a stack trace (#2938)
• Fix dot-separated redirect in config_options.Deprecated(moved_to) (#2963)

Tweaked logic for handling ConfigOption.default (#2938)

Deprecated config option classes: ConfigItems (#2983), OptionallyRequired (#2962), RepoURL (#2927)

Theme updates

• Styles of admonitions in "MkDocs" theme (#2981):

  • Update colors to increase contrast
  • Apply admonition styles also to <details> tag, to support Markdown extensions that provide it (pymdownx.details, callouts)

• Built-in themes now also support these languages:

  • Russian (#2976)
  • Turkish (Turkey) (#2946)
  • Ukrainian (#2980)

Future compatibility

• extra_css: and extra_javascript: warn if a backslash \ is passed to them. (#2930, #2984)

• Show DeprecationWarnings as INFO messages. (#2907)

  If any plugin or extension that you use relies on deprecated functionality of other libraries, it is at risk of breaking in the near future. Plugi...

1.3.1

• Pin Python-Markdown version to <3.4, thus excluding its latest release that breaks too many external extensions (#2893)

• When a Markdown extension fails to load, print its name and traceback (#2894)

• Bugfix for "readthedocs" theme (regression in 1.3.0): add missing space in breadcrumbs (#2810)

• Bugfix: don't complain when a file "readme.md" (lowercase) exists, it's not recognized otherwise (#2852)

• Built-in themes now also support these languages:

  • Italian (#2860)

Other small improvements; see commit log.