Release notes: apply automation also to AA, Nemo (and possibly others)

[fingolfin]

The same automation for the release notes we have here should also be set up for AA, Nemo, and perhaps other of our packages.

Perhaps it would make sense to first implement a few more improvements here, otherwise we'll just have to backport changes over time...

(Though I guess the script itself could also live in a separate repository and be shared from all from there? But then things like the categories must be adjustable via a CSV/JSON/TOML/YAML/... config file or so...)

[thofma]

That would be nice (I already adjusted it to Hecke already with some tweaks, see #4665 (comment)).