Fix admonition special case (custom named admonition)

[choldgraf]

This adds a special case to the "notes/warn/etc" admonition handling.

Admonitions are different because users can specify their own titles. This PR:

• Uses the "note" admonition class by default
• Updates the admonitiontitles dictionary on-the-fly to make it use the user-provided title
• Then makes the admonition behave like any other admonition

This also makes it possible to style the admonition output using the :name: flag, so you can do things like

.. admonition: my title
   :name: warning

   A warning-styled admonition

See the end of the admonitions section here: https://176-130237506-gh.circle-artifacts.com/0/html/demo/demo.html#admonitions

For comparison, note the admonition at the end in the docs is not styled:
https://pandas-sphinx-theme.readthedocs.io/en/latest/demo/demo.html#admonitions

closes #117 and #70

[choldgraf]

@jorisvandenbossche can I get a review on this one? Currently if people use a generic admonition then there's no styling applied...

[jorisvandenbossche]

Hmm, the preview is not loading.
I am not very familiar with custom admonitions. For my education, does the text you put after .. admonition:: then the title?

[choldgraf]

Yep, basically "notes" and "warnings" are just special cases of an admonition. So with the admonition directive you can define custom titles

[jorisvandenbossche]

OK, thanks!

[chipbrock]

Is it possible to style the text formatting within an admonition? I would like for it to be serif so as to be more distinct from the standard sans-serif body font. It seems to inherit from <p>which makes this undoable with my limited css skills.

I can change the formatting of the admonition title (?) in my own css file...but not the body.

This, BTW, is for JupyterBooks that I'm trying to accomplish this. I'd greatly appreciate help with this. thanks.

[jorisvandenbossche]

@chipbrock late reply, but I think that should still be possible by only selecting <p> tags that are inside the admonition div. For example the followins makes all text in the admonition title and body serif:

.admonition p {
 font-family:serif;
}

[jorisvandenbossche]

Ah, I see you also opened #431 about this and there is some discussion there.