Update CHANGELOG.md for 2.22.0

Update CHANGELOG.md

Merge pull request #192 from github/smowton/admin/2.21.3-changelog

Update changelog for 2.21.3

Update changelog for 2.21.2

Changelog: Update release notes for version 2.21.1

Add details about bug fixes in CodeQL analysis for GitHub Actions.
Clarify behavior with `paths-ignore` and `paths` configurations to improve
performance on large codebases.

Update CHANGELOG.md

Merge pull request #191 from github/smowton/admin/update-changelog-2.…

…20.7

Update CHANGELOG.md for release 2.20.7

Update CHANGELOG.md for 2.20.6

Add 2.20.5 to changelog

Update CHANGELOG.md for 2.20.4