Update changelog generation: default github labels and new upstream release

* Use a release version of github-changelog-generator. The gem has had several upstream releases recently fixing most of the issues we encountered. Most importantly the pdk default configuration for labels now works out of the box.
* Start aligning with github's default labels to reduce the effort for publishing a new module
** Add support for github's default labels "bug" and "documentation"
** List github's default labels first in the `configure_sections`