Changelog entry missing

[stefanodavid]

Describe the issue The changelog entries for #263 and #264 are missing

Also restructure the changelog section, by:

• [x] moving each year's changelog to own file
• [x] grouping entries related to the same release (only for 2022, 2021 was :ok:)

https://docs.opendatahub.com/en/latest/changelog.html