`original_app_name` is used to show error message if giving app name is
invalid, it should be shown raw app name.

[ci skip] Doc for shallow: false options should use <tt> for better readability. 

`@changed_attributes` is no longer used since #30985.

* s/Postgres/PostgreSQL/
* s/MYSQL/MySQL/, s/Mysql/MySQL/
* s/Sqlite/SQLite/

Replaced all newly added them after 6089b314.

Fixed description of the `cache_key_with_version` method [skip ci]

Add `after_save_commit` callback as shortcut for `after_commit :hook, on: [ :create, :update ]`. (#35804)

Honor shallow: false on nested resources

Add attachment and attachments field generators

Hash / HashWithIndifferentAccess speed improvements

* Remove unnecessary variable from ActionCable.createWebSocketURL

* Improve ActionCable test by creating the Consumer before reassigning URL

With this change, the test now actually verifies that the Consumer's url
property changes dynamically (from testURL to `${testURL}foo`).

* Fix alphabetization of ActionCable exports

Add db:prepare rake task.

[ci skip] Updated the doc after renaming Template::File -> Template::RawFile in #35826

Rename `Template::File` to `Template::RawFile`

Rename `connection` option to `database` in `dbconsole` command

[ci skip] Fix typo for recieve -> receive

We introduced `connection` option for specifying spec with 1acd9a64.
But now we are using the `database` to specify the same value in other commands.

* https://github.com/rails/rails/blob/0a0f115031b64b5335fa88543c40df4194dfb428/activerecord/lib/rails/generators/active_record/migration/migration_generator.rb#L11
* https://github.com/rails/rails/blob/0a0f115031b64b5335fa88543c40df4194dfb428/activerecord/lib/rails/generators/active_record/model/model_generator.rb#L17

The options provided to the users should be uniform. Since the term
"database" is used in rake task etc, So I want to be able to use it in
`dbconsole` command.

Also I deprecated the `connection` option because I think that it
would be confusing if there are multiple options to specify a same value.

Add Changelog entry for #35732.

url -> URL where apt except inside actionpack/

url -> URL where apt inside actionpack/

Include final newline in generated .ruby-version