Merge pull request #16706 from tomkadwill/documented_include_record_param

[ci skip] Updated include to reference record parameter for rdoc
Merge pull request #16705 from tomkadwill/documented_many_block_param

[ci skip] Updated documentation syntax of block parameter for rdoc
Adjusted punctuation and grammar for Form Helpers guide [ci skip]
Merge pull request #16708 from zzak/bcjordan-patch-1

Adjusted punctuation and grammar for Form Helpers guide [ci skip]
[ci skip] Updated documentation syntax of other parameter for rdoc
Merge pull request #16713 from tomkadwill/documented_eqls_other_param

[ci skip] Updated documentation syntax of other parameter for rdoc
[ci skip] Modify a web-console PR link
Merge pull request #16715 from y-yagi/update_4_2_release_notes

[ci skip] Modify a web-console PR link for release noted
Use less iterations for KeyGenerator in tests

This commit improves performance of cookie tests:

Ruby  |   After  |   Before
----- | --------:| --------:
MRI   |    5.03s |     9.28s
JRuby |   25.45s |  1648.23s

Please note the improvement for JRuby.
Merge pull request #16661 from edogawaconan/doc-fix

Update documentation to match change in #5942 [ci skip]
minor changelog formatting changes.
fix broken `gem` method with non-String arguments. Closes #16709.

This was caused by #15327.
Fix spelling. [CI SKIP]
Merge pull request #16719 from tgxworld/fix_spelling_in_changelog

Fix spelling. [CI SKIP]
Correctly detect mutation on serialized columns mapping to binary

Fixes #16701
[ci skip] Update 4_2_release notes
[ci skip] Fix typo of `collection_singular_ids=` method.
[ci skip] Fix typo of `collection=` method.
Merge pull request #16721 from yui-knk/fix/guides_association_basics

[ci skip] Fix typo of `collection=` method.
Merge pull request #16722 from yui-knk/fix/guides_association_basics2

[ci skip] Fix typo of `collection_singular_ids=` method.