Enrich changelog output generated by GitLab by grouping commits per Git trailer tags
When the API mentioned in #1367 is in place, we want to enrich the changelog output. For example, we want to group changelog entries per category such as bug/feature/performance.
To enable this, the API should have an option to group entries per the value of a Git trailer tag. For example, you may have commits with trailer tags such as
Caterory: Fixed and
Category: Performance. If you then tell the API to group by the
Category trailer, it will generate sections such as:
### Fixed ... ### Performance ...