Automated CHANGELOG entries creation

Problem to solve

New entries are added to CHANGELOG ad-hoc, which results in more manual work and inconsistencies in the changelog entries.

Proposal

Implement a mechanism similar to the one used gitlab-org/gitlab (https://docs.gitlab.com/ee/development/changelog.html). Each MR that introduces significant user-facing change would create a changelog entry. These entries would get compiled into a version changelog during the release of the new version.

Improving even further we could utilize the releases feature which we've started using for GitLab. Example: https://gitlab.com/gitlab-org/gitlab/-/releases#v13.1.0-ee

Links / references

• Example changelog entries: https://gitlab.com/gitlab-org/gitlab/tree/master/changelogs/unreleased/
• Ruby script for generating changelog entries: https://gitlab.com/gitlab-org/gitlab/-/blob/master/bin/changelog