Capitalize headings to match style guidelines

Fix all headings to follow Rails Guides Guidelines

guides/source/action_cable_overview.md

@@ -792,7 +792,7 @@ connections as you have workers. The default worker pool size is set to 4, so
 that means you have to make at least 4 database connections available.
 You can change that in `config/database.yml` through the `pool` attribute.
 
-### Client-side logging
+### Client-side Logging
 
 Client-side logging is disabled by default. You can enable this by setting the `ActionCable.logger.enabled` to true.
 

guides/source/action_controller_overview.md

@@ -142,7 +142,7 @@ When this form is submitted, the value of `params[:client]` will be `{ "name" =>
 
 The `params` object acts like a Hash, but lets you use symbols and strings interchangeably as keys.
 
-### JSON parameters
+### JSON Parameters
 
 If you're writing a web service application, you might find yourself more comfortable accepting parameters in JSON format. If the "Content-Type" header of your request is set to "application/json", Rails will automatically load your parameters into the `params` hash, which you can access as you would normally.
 
@@ -680,7 +680,7 @@ If you use the cookie session store, this would apply to the `session` and
 
 [`cookies`]: https://api.rubyonrails.org/classes/ActionController/Cookies.html#method-i-cookies
 
-Rendering XML and JSON data
+Rendering XML and JSON Data
 ---------------------------
 
 ActionController makes it extremely easy to render `XML` or `JSON` data. If you've generated a controller using scaffolding, it would look something like this:
@@ -1274,7 +1274,7 @@ NOTE: Certain exceptions are only rescuable from the `ApplicationController` cla
 
 [`rescue_from`]: https://api.rubyonrails.org/classes/ActiveSupport/Rescuable/ClassMethods.html#method-i-rescue_from
 
-Force HTTPS protocol
+Force HTTPS Protocol
 --------------------
 
 If you'd like to ensure that communication to your controller is only possible

guides/source/action_mailbox_basics.md

@@ -340,15 +340,15 @@ your job queue being able to hold jobs for that long.)
 
 [`config.action_mailbox.incinerate_after`]: configuring.html#config-action-mailbox-incinerate-after
 
-## Working with Action Mailbox in development
+## Working with Action Mailbox in Development
 
 It's helpful to be able to test incoming emails in development without actually
 sending and receiving real emails. To accomplish this, there's a conductor
 controller mounted at `/rails/conductor/action_mailbox/inbound_emails`,
 which gives you an index of all the InboundEmails in the system, their
 state of processing, and a form to create a new InboundEmail as well.
 
-## Testing mailboxes
+## Testing Mailboxes
 
 Example:
 

guides/source/action_mailer_basics.md

@@ -22,7 +22,7 @@ What is Action Mailer?
 Action Mailer allows you to send emails from your application using mailer classes
 and views.
 
-### Mailers are similar to controllers
+### Mailers are Similar to Controllers
 
 They inherit from [`ActionMailer::Base`][] and live in `app/mailers`. Mailers also work
 very similarly to controllers. Some examples of similarities are enumerated below.
@@ -259,7 +259,7 @@ access it with the [`message`][] method on the `ActionMailer::MessageDelivery` o
 [`message`]: https://api.rubyonrails.org/classes/ActionMailer/MessageDelivery.html#method-i-message
 [`with`]: https://api.rubyonrails.org/classes/ActionMailer/Parameterized/ClassMethods.html#method-i-with
 
-### Auto encoding header values
+### Auto Encoding Header Values
 
 Action Mailer handles the auto encoding of multibyte characters inside of
 headers and bodies.
@@ -352,7 +352,7 @@ Action Mailer 3.0 makes inline attachments, which involved a lot of hacking in p
     <%= image_tag attachments['image.jpg'].url, alt: 'My Photo', class: 'photos' %>
     ```
 
-#### Sending Email To Multiple Recipients
+#### Sending Email to Multiple Recipients
 
 It is possible to send email to one or more recipients in one email (e.g.,
 informing all admins of a new signup) by setting the list of emails to the `:to`
@@ -374,7 +374,7 @@ end
 The same format can be used to set carbon copy (Cc:) and blind carbon copy
 (Bcc:) recipients, by using the `:cc` and `:bcc` keys respectively.
 
-#### Sending Email With Name
+#### Sending Email with Name
 
 Sometimes you wish to show the name of the person instead of just their email
 address when they receive the email. You can use [`email_address_with_name`][] for
@@ -473,7 +473,7 @@ You can also consider using the [`append_view_path`][] method.
 [`append_view_path`]: https://api.rubyonrails.org/classes/ActionView/ViewPaths/ClassMethods.html#method-i-append_view_path
 [`prepend_view_path`]: https://api.rubyonrails.org/classes/ActionView/ViewPaths/ClassMethods.html#method-i-prepend_view_path
 
-#### Caching mailer view
+#### Caching Mailer View
 
 You can perform fragment caching in mailer views like in application views using the [`cache`][] method.
 
@@ -625,7 +625,7 @@ NOTE: non-`GET` links require [rails-ujs](https://github.com/rails/rails/blob/ma
 [jQuery UJS](https://github.com/rails/jquery-ujs), and won't work in mailer templates.
 They will result in normal `GET` requests.
 
-### Adding images in Action Mailer Views
+### Adding Images in Action Mailer Views
 
 Unlike controllers, the mailer instance doesn't have any context about the
 incoming request so you'll need to provide the `:asset_host` parameter yourself.

guides/source/action_text_overview.md

@@ -25,7 +25,7 @@ RichText model that's associated with any existing Active Record model in the ap
 Any embedded images (or other attachments) are automatically stored using
 Active Storage and associated with the included RichText model.
 
-## Trix compared to other rich text editors
+## Trix Compared to Other Rich Text Editors
 
 Most WYSIWYG editors are wrappers around HTML’s `contenteditable` and `execCommand` APIs,
 designed by Microsoft to support live editing of web pages in Internet Explorer 5.5,
@@ -61,7 +61,7 @@ After the installation is complete, a Rails app should have the following change
 
 2. The `trix` stylesheet will be included together with Action Text styles in your `application.css` file.
 
-## Creating Rich Text content
+## Creating Rich Text Content
 
 Add a rich text field to an existing model:
 
@@ -111,7 +111,7 @@ end
 
 [`rich_text_area`]: https://api.rubyonrails.org/classes/ActionView/Helpers/FormHelper.html#method-i-rich_text_area
 
-## Rendering Rich Text content
+## Rendering Rich Text Content
 
 By default, Action Text will render rich text content inside an element with the
 `.trix-content` class:
@@ -214,7 +214,7 @@ By default, all `ActiveRecord::Base` descendants mix-in
 
 [global-id]: https://github.com/rails/globalid#usage
 
-## Avoid N+1 queries
+## Avoid N+1 Queries
 
 If you wish to preload the dependent `ActionText::RichText` model, assuming your rich text field is named `content`, you can use the named scope:
 
@@ -223,7 +223,7 @@ Message.all.with_rich_text_content # Preload the body without attachments.
 Message.all.with_rich_text_content_and_embeds # Preload both body and attachments.
 ```
 
-## API / Backend development
+## API / Backend Development
 
 1. A backend API (for example, using JSON) needs a separate endpoint for uploading files that creates an `ActiveStorage::Blob` and returns its `attachable_sgid`:
 

guides/source/action_view_helpers.md

@@ -12,7 +12,7 @@ After reading this guide, you will know:
 
 --------------------------------------------------------------------------------
 
-Overview of helpers provided by Action View
+Overview of Helpers Provided by Action View
 -------------------------------------------
 
 WIP: Not all the helpers are listed here. For a full list see the [API documentation](https://api.rubyonrails.org/classes/ActionView/Helpers.html)

guides/source/action_view_overview.md

@@ -204,7 +204,7 @@ This will render a file named `_menu.html.erb` at that point within the view tha
 
 That code will pull in the partial from `app/views/shared/_menu.html.erb`.
 
-#### Using Partials to simplify Views
+#### Using Partials to Simplify Views
 
 One way to use partials is to treat them as the equivalent of subroutines; a way to move details out of a view so that you can grasp what's going on more easily. For example, you might have a view that looks like this:
 
@@ -223,7 +223,7 @@ One way to use partials is to treat them as the equivalent of subroutines; a way
 
 Here, the `_ad_banner.html.erb` and `_footer.html.erb` partials could contain content that is shared among many pages in your application. You don't need to see the details of these sections when you're concentrating on a particular page.
 
-#### `render` without `partial` and `locals` options
+#### `render` without `partial` and `locals` Options
 
 In the above example, `render` takes 2 options: `partial` and `locals`. But if
 these are the only options you want to pass, you can skip using these options.
@@ -239,7 +239,7 @@ You can also do:
 <%= render "product", product: @product %>
 ```
 
-#### The `as` and `object` options
+#### The `as` and `object` Options
 
 By default `ActionView::Partials::PartialRenderer` has its object in a local variable with the same name as the template. So, given:
 
@@ -398,7 +398,7 @@ views are located. By default, it only looks inside the `app/views` directory.
 We can add other locations and give them certain precedence when resolving
 paths using the `prepend_view_path` and `append_view_path` methods.
 
-### Prepend view path
+### Prepend View Path
 
 This can be helpful for example when we want to put views inside a different
 directory for subdomains.
@@ -411,7 +411,7 @@ prepend_view_path "app/views/#{request.subdomain}"
 
 Then Action View will look first in this directory when resolving views.
 
-### Append view path
+### Append View Path
 
 Similarly, we can append paths:
 

guides/source/active_job_basics.md

@@ -326,7 +326,7 @@ class ApplicationJob < ActiveJob::Base
 end
 ```
 
-### Available callbacks
+### Available Callbacks
 
 * [`before_enqueue`][]
 * [`around_enqueue`][]
@@ -377,7 +377,7 @@ UserMailer.welcome(@user).deliver_later # Email will be localized to Esperanto.
 ```
 
 
-Supported types for arguments
+Supported Types for Arguments
 ----------------------------
 
 ActiveJob supports the following types of arguments by default:
@@ -496,7 +496,7 @@ If an exception from a job is not rescued, then the job is referred to as "faile
 
 [`rescue_from`]: https://api.rubyonrails.org/classes/ActiveSupport/Rescuable/ClassMethods.html#method-i-rescue_from
 
-### Retrying or Discarding failed jobs
+### Retrying or Discarding Failed Jobs
 
 A failed job will not be retried, unless configured otherwise.
 

guides/source/active_model_basics.md

@@ -203,7 +203,7 @@ class Person
 end
 ```
 
-#### Querying object directly for its list of all changed attributes.
+#### Querying an Object Directly for its List of All Changed Attributes
 
 ```irb
 irb> person = Person.new
@@ -231,7 +231,7 @@ irb> person.changes
 => {"first_name"=>[nil, "First Name"]}
 ```
 
-#### Attribute-based accessor methods
+#### Attribute-based Accessor Methods
 
 Track whether the particular attribute has been changed or not.
 

guides/source/active_record_encryption.md

@@ -66,7 +66,7 @@ But, under the hood, the executed SQL looks like this:
 INSERT INTO `articles` (`title`) VALUES ('{\"p\":\"n7J0/ol+a7DRMeaE\",\"h\":{\"iv\":\"DXZMDWUKfp3bg/Yu\",\"at\":\"X1/YjMHbHD4talgF9dt61A==\"}}')
 ```
 
-#### Important: About storage and column size
+#### Important: About Storage and Column Size
 
 Encryption requires extra space because of Base64 encoding and the metadata stored along with the encrypted payloads. When using the built-in envelope encryption key provider, you can estimate the worst-case overhead at around 255 bytes. This overhead is negligible at larger sizes. Not only because it gets diluted but because the library uses compression by default, which can offer up to 30% storage savings over the unencrypted version for larger payloads.
 

guides/source/active_record_multiple_databases.md

@@ -32,7 +32,7 @@ The following features are not (yet) supported:
 
 * Load balancing replicas
 
-## Setting up your application
+## Setting up Your Application
 
 While Rails tries to do most of the work for you there are still some steps you'll
 need to do to get your application ready for multiple databases.
@@ -274,7 +274,7 @@ $ bin/rails generate scaffold Dog name:string --database animals --parent Animal
 This will skip generating `AnimalsRecord` since you've indicated to Rails that you want to
 use a different parent class.
 
-## Activating automatic role switching
+## Activating Automatic Role Switching
 
 Finally, in order to use the read-only replica in your application, you'll need to activate
 the middleware for automatic switching.
@@ -332,7 +332,7 @@ config.active_record.database_resolver = ActiveRecord::Middleware::DatabaseSelec
 config.active_record.database_resolver_context = MyCookieResolver
 ```
 
-## Using manual connection switching
+## Using Manual Connection Switching
 
 There are some cases where you may want your application to connect to a writer or a replica
 and the automatic connection switching isn't adequate. For example, you may know that for a
@@ -367,7 +367,7 @@ ActiveRecord::Base.connected_to(role: :reading, prevent_writes: true) do
 end
 ```
 
-## Horizontal sharding
+## Horizontal Sharding
 
 Horizontal sharding is when you split up your database to reduce the number of rows on each
 database server, but maintain the same schema across "shards". This is commonly called "multi-tenant"
@@ -432,7 +432,7 @@ ActiveRecord::Base.connected_to(role: :reading, shard: :shard_one) do
 end
 ```
 
-## Activating automatic shard switching
+## Activating Automatic Shard Switching
 
 Applications are able to automatically switch shards per request using the provided
 middleware.
@@ -515,7 +515,7 @@ end
 `ActiveRecord::Base.connected_to` maintains the ability to switch
 connections globally.
 
-### Handling associations with joins across databases
+### Handling Associations with Joins across Databases
 
 As of Rails 7.0+, Active Record has an option for handling associations that would perform
 a join across multiple databases. If you have a has many through or a has one through association

guides/source/active_record_postgresql.md

@@ -672,7 +672,7 @@ irb> Article.count
 NOTE: This application only cares about non-archived `Articles`. A view also
 allows for conditions so we can exclude the archived `Articles` directly.
 
-Structure dumps
+Structure Dumps
 --------------
 
 If your `config.active_record.schema_format` is `:sql`, Rails will call `pg_dump` to generate a

guides/source/active_record_querying.md

@@ -899,7 +899,7 @@ FROM orders
 GROUP BY created_at
 ```
 
-### Total of grouped items
+### Total of Grouped Items
 
 To get the total of grouped items on a single query, call [`count`][] after the `group`.
 
@@ -1604,7 +1604,7 @@ end
 
 [`scope`]: https://api.rubyonrails.org/classes/ActiveRecord/Scoping/Named/ClassMethods.html#method-i-scope
 
-### Passing in arguments
+### Passing in Arguments
 
 Your scope can take arguments:
 
@@ -1636,7 +1636,7 @@ These methods will still be accessible on the association objects:
 irb> author.books.costs_more_than(100.10)
 ```
 
-### Using conditionals
+### Using Conditionals
 
 Your scope can utilize conditionals:
 
@@ -1658,7 +1658,7 @@ end
 
 However, there is one important caveat: A scope will always return an `ActiveRecord::Relation` object, even if the conditional evaluates to `false`, whereas a class method, will return `nil`. This can cause `NoMethodError` when chaining class methods with conditionals, if any of the conditionals return `false`.
 
-### Applying a default scope
+### Applying a Default Scope
 
 If we wish for a scope to be applied across all queries to the model we can use the
 [`default_scope`][] method within the model itself.
@@ -1720,7 +1720,7 @@ irb> Book.new
 
 [`default_scope`]: https://api.rubyonrails.org/classes/ActiveRecord/Scoping/Default/ClassMethods.html#method-i-default_scope
 
-### Merging of scopes
+### Merging of Scopes
 
 Just like `where` clauses, scopes are merged using `AND` conditions.
 
@@ -1895,7 +1895,7 @@ There are some examples below. This guide won't cover all the possibilities, jus
 When an Active Record method is called, the query is not immediately generated and sent to the database.
 The query is sent only when the data is actually needed. So each example below generates a single query.
 
-### Retrieving filtered data from multiple tables
+### Retrieving Filtered Data from Multiple Tables
 
 ```ruby
 Customer
@@ -1914,7 +1914,7 @@ INNER JOIN reviews
 WHERE (reviews.created_at > '2019-01-08')
 ```
 
-### Retrieving specific data from multiple tables
+### Retrieving Specific Data from Multiple Tables
 
 ```ruby
 Book