Updating select helper doc [ci skip]
Fix misspelling in references docs
Update documentation on group method to indicate it takes an array

The group method also takes an array, however this isn't immediately
clear by reading the source since it delegates this method. If you
trace it back to the AREL building you can see that it does support
an array.

Shoutout to @betovelandia for pointing this out.
Mention required glob param name in match docs for mapper

THe match documentation doesn't mention any requirement of the
parameter name requirement for matches. However, including a
bare glob character without a variable assignment causes a
parse error.
Clarify environment_name for logs

[ci skip]
Ensure we are returning either `true` or `false` for `#==`

460eb83d cused `ActiveRecord::Base#==` to sometimes return `nil` in some cases,
this ensures we always return a boolean value. Also fixed a similar problem in
AR reflections.
copy edit [ci skip]
Merge branch 'master' of github.com:rails/docrails
Merge pull request #14526 from chancancode/fix_ar_equality

Ensure we are returning either `true` or `false` for `#==`
Improve form_for documentation

Improve documentation about formats in form_for with custom urls