Merge content CHANGELOG.md into changes.md

[kaklakariada]

Changelog file https://github.com/itsallcode/openfasttrace/blob/main/doc/CHANGELOG.md is deprecated. We now use https://github.com/itsallcode/openfasttrace/blob/main/doc/changes/changes.md and individual files for each version.

To avoid confusion we should merge the content of CHANGELOG.md into the new file and delete it.