Deprecate `Module#reachable?` method

Add `with_attached_*` scope to `has_one_attached` macro

Update Layouts and Rendering in Rails [ci skip]

make documentation consistent with  KeyError message 

Use RESTful instead of restful

make create_join_table compatible.

Use credentials in `storage.yml` template

Follow up of #30650

According to #30067:

> This PR will deprecate secrets.yml* and instead adopt
> config/credentials.yml.enc to signify what these secrets are specifically
> for: Keeping API keys, database passwords, and any other integration
> credentials in one place.

[ci skip] since only comments are being edited.

Add :comment option for add_column [ci skip]

Update action_controller_overview.md [ci skip]

Remove unused `NumberToRoundedConverter#digits_and_rounded_number`

`digits_and_rounded_number` is unused since #26628

* For avoiding N+1 problem, added `with_attached_*` scope to
  `has_one_attached` macro.

Use the default Capybara registered puma server configuration

Use ApplicationJob instead of ActiveJob::Base in guide [ci skip]

Add section to guides for discarding and retrying active jobs [ci skip]

Fix quotes [ci skip]

Upcase js [ci skip]

Remove "the" [ci skip]

Add test validating that Model.attribute_names cache is busted

Since we have `Preloader#preload`, `Preloader::Association#preload` is a
little confusing. And also, since the `preload` method is an abstract
method, it is hard to read where `associated_records_by_owner` is
called. This refactors `Preloader::Association` to ease to read where
`associated_records_by_owner` is called.

Remove unused require in ActiveStorage::Variation