Commit and update CHANGELOG.md

Problem

When a gem released we already create a changelog.md as part of the release artifact.

In the Ruby community is not uncommon the have a CHANGELOG.md or HISTORY.md being part of the repository. This is file is currently not generated by this CI component.

Proposed solution

Allow this CI component to generate and commit CHANGELOG.md during the release process.

Implementation guide

1. Post a suggestion comment on the MR to add update CHANGELOG.md
   • What happens if CHANGELOG.md is missing?

OR

2. Push a commit to the MR with the updated CHANGELOG.md