additional note about routes in functional tests for engines [ci skip]
Improve Contributing to Rails Guide

Logically group the content, so it makes more sense if someone tries to read from start of page to end of page. [ci skip]
Add documentation for Thread#freeze
Instead boat load of libraries, simply say StdLib
Use path where extensions are defined, not used

For consistency with all other documentation, point to where these core
extensions are defined, not where the example code comes from.

[ci skip]
Document LoadError core extensions

[ci skip]
Fix a few grammar issues. [ci skip]
Correct docs as singlton true is not returned here

[ci skip]
The comparison between `Relation` and `CollectionProxy` should be consistent.

Example:

    author.posts == Post.where(author_id: author.id)
    # => true
      Post.where(author_id: author.id) == author.posts
    # => true

Fixes #13506
Make the comparison between 'Relation' and 'AssociationRelation'
consistent.
Ensure that the comparison between 'CollectionProxy' and 'AssociationRelation' is consistent.
remove branching logic from calls to find_nth
only add the offset and index when we need to
don't bother with an offset if the offset is zero

we're guaranteed to pass a numeric value for offset, so if it's zero,
just don't add an offset to the query
Bundle tzinfo-data on :x64_mingw (64-bit Ruby on Windows).
Merge pull request #14720 from philr/tzinfo_data_x64_mingw

Bundle tzinfo-data on :x64_mingw (64-bit Ruby on Windows).
Fix a few typos [ci skip]

This is a follow up to 545afc15.
CollectionHelpers now accepts a readonly option
Missing 'are' in note - [ci skip]

This is in the note at the end of Section 2: Controller Naming Convention.  [ci skip]
Merge pull request #14725 from afshinator/patch-1

Missing 'are' in note - [ci skip]