quick formatting pass through CHANGELOGS. [ci skip].
Add missing tests for invalid names in `rails plugin new`

* Test for: Invalid plugin name, because of reserved rails word.
* Test for: Invalid plugin name because of constant name that is already in use.
Fix typo in AMo docs [ci skip]
Merge pull request #13611 from robinboening/plugin_generator_tests

Add missing tests for invalid names in `rails plugin new` generator
Fix rdoc markup [ci skip]

Wrapping symbols with + does not work, we must use <tt> instead.
Fix typo [ci skip]
Fix AR connection resolver docs to return a hash with string keys [ci skip]
Fix typo in AS changelog, improve highlight [ci skip]
add example to the CHANGELOG entry from 3a48b83e5 [ci skip].

/cc @pixeltrix
Fix: ActiveRecord::Store TypeError conversion when using YAML coder

Renaming the test accordingly to its behaviour

Adding 'Fixes' statement to changelog

Improving tests legibility & changelog

Undoing mistakenly removed empty line & further improving changelog
Merge pull request #13593 from oliveiraethales/store_yaml_coder

Fix: ActiveRecord::Store TypeError conversion when using YAML coder
Remove warnings in test suite

lib/active_record/store.rb:79: warning: method redefined; discarding old color=
lib/active_record/store.rb:79: warning: previous definition of color= was here
lib/active_record/store.rb:83: warning: method redefined; discarding old color
lib/active_record/store.rb:83: warning: previous definition of color was here
Merge pull request #13616 from zirni/remove_warnings

Remove warnings in test suite
activerecord: Initialize Migration with version from MigrationProxy.
Add 'e' var on rescue DalliError, in order to log it
Merge pull request #13617 from arthurnn/error_var

Add 'e' var on rescue DalliError, in order to log it
Use a better method name to check the requirement of password confirmation

Also improve changelog entries related to secure password to proper
highlight.
Make change_table use object of current database adapter

  - Earlier, change_table was creating database-agnostic object.
  - After this change, it will create correct object based on current
    database adapter.
  - This will ensure that create_table and change_table will get same objects.
  - This makes update_table_definition method public and nodoc.
  - Fixes #13577 and #13503
Merge pull request #13597 from prathamesh-sonpatki/hstore_migration

Make change_table use object of current database adapter
Fix typo in image_tag documentation

image_tag only supports :alt and :size as additional keys, not three.