Normalize whitespace for Hash#compact documentation

This is a similar change that occurred for Hash#except in #21087.

And make sure that it doesn't even try to call the method in the target.

Build action_cable.js with Blade

Introduce Module#delegate_missing_to

Cloning depth set to 1

Improved commands in README with markdown formatting

Introduced in d6f2000a and was only used by Action Cable. Now handled by Action Cable’s assets:compile task.

Adding '$' to emulate shell syntax

[ci skip]

Use RAILS_MAX_THREADS as pool size on all adapters

[] and read_attribute are not aliases [ci skip]

The `#[]` method *used to be* an alias of `#read_attribute`, but since Rails 4
(10f6f90d), it will raise an exception for
missing attributes. Saying that it is an alias is confusing.

When RAILS_MAX_THREADS is set, the postgresql adapter uses it as the
connection pool size, so that there are always enough connections
available to serve Action Cable requests.

The same logic applies when using any other adapter.

This reverts commit 28492204.

Reason: `suppress` without an argument doesn't actually tell what is
supressing. Also, it can be confused with ActiveRecord::Base#suppress.

* Add default exceptions affected by suppress

    suppress { do_something_that_might_fail }

    # instead of

    begin
      do_something_that_might_fail
    rescue
    end

    # or

    do_something_that_might_fail rescue nil

* Do not add default exceptions list constant

[Rafael Mendonça França + Alexey Zapparov]

remove deprecated `Module#qualified_const_` from guide [ci skip]

Fix and optimize scaffold CSS

CSRF verification for non-XHR GET requests (cross-origin `<script>`
tags) didn't check this flag before logging failures.

Setting `config.action_controller.log_warning_on_csrf_failure = false`
now disables logging for these CSRF failures as well.

Closes #25086.
Signed-off-by: NJeremy Daer <jeremydaer@gmail.com>

Follow up to #17845.

Apps that depend on Action Cable don't need Blade for app development,
so we can remove the gem dependency.

We do need Blade for Action Cable dev, so we bundle it in the Gemfile.
Signed-off-by: NJeremy Daer <jeremydaer@gmail.com>

Change comments to not exceed 80 characters

Remove space, properly italicize

Add backticks to `config/secrets.yml`

Difference in rendering --> https://gist.github.com/maclover7/a50ff9231eb825c39c77cd5858af6d9a

[ci skip]

[ci skip]

Pass over Action Cable docs

[ci skip]

Un-hide helper and assets options for controller generator

Add missing `the`

Introduce AR::TransactionSerializationError for transaction serialization failures or deadlocks

[ci skip]

* #uniq will be deprecated, see: rails/rails@adfab2d