All other Rails components feature this section, Action Cable should
have it as well.

[ci skip]

- Only Action Cable README did not have this section, all of the other
  READMEs have this section.

- Remove "Configuration", "Running the server", "Dependencies" and "Deployment"
  sections from the Action Cable README as they are already duplicated in the
  Action Cable overview guide.

Added 'sh' for markdown formatting as bash.

Sorry, forgot to include in my main PR :(

[ci skip]

[Jon Moss, Zach Schneider]

In #23935, cable file was to be provided by the javascript instead of coffeescript,
doc was also been modified to use javascript.

[ci skip]

default worker pool size was changed from 100 to 4 at #24376

Follow up to 8b69f1ee

* Fix typos/grammar errors
* Make capitalization/naming consistent

This PR checks all active Action Cable documentation for typos and other
fixes. It aims to make sure that when Rails 5 is released, that the
Action Cable docs are up to snuff with the other documentation included
with Rails.

[ci skip]

[ci skip]

`faye-websocket` gem is no longer used from 322dca29.

Some existing examples used ActionCable.server.config but for
configuring allowed_request_origins that is overridden in development
mode. The correct place to set that is
Rails.application.config.action_cable which the ActionCable initializer
loads from. I thought the other two examples should be changed as well
just in case a default value that would override a configured value is
introduced for either log_tags or disable_request_forgery_protection in
the future.

[ci skip]

Since #23152 eliminated the EventMachine dependency, we don’t need to
explicitly mention EventMachine.

Nevertheless, I'm not 100% sure about saying "the websocket-driver loop"
driver… any suggestions, @matthewd or @pixeltrix ? 😅

[ci skip]

This changed in #22950.

I believe the paragraph starting with "This relies" belongs with the one above it.

* Clarify wording around how defaults work
* Clarify wording around what formatting versus information is required
* Separate consumer configuration section since it is important and wordy
* Add additional explanation of options for setting consumer configuration
* Consolidate consumer configuration information to reduce confusion

This reverts commit d0393fcc, reversing
changes made to 3b7ccadf.

Mounting it as prescribed here:

https://github.com/rails/rails/blob/0d1d50c2db40ea1a9d3bebfb0c35da43bbd4d27f/railties/lib/rails/generators/rails/app/templates/config/routes.rb#L5

* Add link to API documentation
* Link to issue tracker for rails/rails (instead of rails/actioncable)
* Add link to rails-core mailing list for feature requests