Readme/Changelog: update for release of v 1.2.2

Includes:
* Mention of all relevant changes.
* Adding a link for the version diff.
* Updating the `VERSION` document with the version nr for the release.

Author: jrfnl

CHANGELOG.md

@@ -9,6 +9,16 @@ This projects adheres to [Keep a CHANGELOG](http://keepachangelog.com/) and uses
 
 _Nothing yet._
 
+## [1.2.2] - 2024-09-10
+
+This is a maintenance release.
+
+### Changed
+* All functionality is now also tested against PHP 8.3 and 8.4.
+* Miscellaneous updates to the development environment and CI scripts, including a contribution by [@fredden].
+* General housekeeping.
+
+
 ## [1.2.1] - 2023-01-05
 
 ### Changed
@@ -75,6 +85,7 @@ Initial release containing:
 
 
 [Unreleased]: https://github.com/PHPCSStandards/PHPCSDevTools/compare/stable...HEAD
+[1.2.2]: https://github.com/PHPCSStandards/PHPCSDevTools/compare/1.2.1...1.2.2
 [1.2.1]: https://github.com/PHPCSStandards/PHPCSDevTools/compare/1.2.0...1.2.1
 [1.2.0]: https://github.com/PHPCSStandards/PHPCSDevTools/compare/1.1.1...1.2.0
 [1.1.1]: https://github.com/PHPCSStandards/PHPCSDevTools/compare/1.1.0...1.1.1
@@ -83,5 +94,6 @@ Initial release containing:
 
 [Composer PHPCS plugin]: https://github.com/PHPCSStandards/composer-installer
 
-[@dingo_d]: https://github.com/dingo-d
+[@dingo_d]:   https://github.com/dingo-d
+[@fredden]:   https://github.com/fredden
 [@GaryJones]: https://github.com/GaryJones

VERSION

@@ -1 +1 @@
-1.2.1
+1.2.2