Should escape regexp wildcard character `.`

`.` is regexp meta character. It should be escape for `assert_match`
correctly.

When an attribute is assigned, we determine if it was already marked as
changed so we can determine if we need to clear the changes, or mark it
as changed. Since this only affects the `attributes_changed_by_setter`
hash, in-place changes are irrelevant to this process. Since calculating
in-place changes can be expensive, we can just skip it here.

I also added a test for the only edge case I could think of that would
be affected by this change.

[ci skip] Move a introduction of `Module.nesting`

Use existing constant for joining instead of '_'

remove reference to `Logger` core extensions from guide [ci skip]

nodoc ActionView::ModelNaming module

- Its only used by ActionView internals and not supposed to be used
  through public API.

[ci skip] fix positions of parentheses

Move a introduction of `Module.nesting` to the beginning of sentence.
This change will help reader to try to dump `nesting`.

Eliminate a ruby warning in a test in Action View

This eliminates the warning below:

  actionview/test/template/form_helper_test.rb:913: warning: method redefined; discarding old id_came_from_user?
  actionview/test/template/form_helper_test.rb:104: warning: previous definition of id_came_from_user? was here

 Fixed test for assert_welcome

Thanks @carlosantoniodasilva 💛

Removed documentation of deprecated removed methods

 - Test was wrongly using assert with assignment statement.

Fix a false assertion

#assert was used when it should be assert_equal.

[ci skip] Change to the passive voice

Consistent anchor text in nav links, new image [ci skip]

Update Molde Generator Usage

A little performance improvement using 'take' method over 'first'

Fix hwia isolated tests

- Fixed the wrong use of with_indifferent_access on hash in the test which failed for isolated tests
- Renamed to appropriately specify what the test does

Fixed extraneous quoting

Typo fix

Including has_secure_token generator

Fix assignment for frozen value in HWIA

Underscore typo [ci skip]