Move to_param to to_query, also Improve tests
remove unneeded test model for ActiveModel test cases.
Add link to minitest rdoc & github
[ci skip] Use appropriate mailer syntax.

Reference: https://github.com/rails/rails/commit/f7e4362011ceb1317fd401125d48d7ccb9a1079c
[ci skip] Remove duplicated last! section.

Reference: https://github.com/rails/rails/commit/d4fd0bd17709735ac91e434c94fe99429f078c6e

cc @schneems
Performed Returns true if redirect/render has happened
missing activesupport test coverage
[ci skip] Normalize all localhost linking.
Fix AC::TemplateAssertions instance variables not resetting.

Fixes https://github.com/rails/rails/issues/16119.
[ci skip] Fix code in Routing Guide
Merge pull request #16236 from y-yagi/patch-1

[ci skip] Fix code in Routing Guide
Remove not-required file class/subclasses
Generator guide grammatical error fixed [ci skip]
Merge pull request #16240 from siddharthbhagwan/master

Generators guide grammatical error fixed [ci skip]
Touch option description grammatical error fixed [ci skip]
Merge pull request #16242 from vadivelan-k/content_verifier

Touch option description grammatical error fixed [ci skip]
Merge pull request #16239 from akshay-vishnoi/remove-require

Remove not-required file class/subclasses
Merge pull request #16232 from egilburg/activesupport_coverage

Added some missing activesupport test coverage
Remove the side-effects of validates_presence_of.
Merge pull request #16248 from zuhao/refactor_activerecord_presence_validation_test

Remove the side-effects of validates_presence_of.