The current way to define a news entry in Home-Manager is error prone
(since you need to type the date manually) and also it is common cause
of conflicts after merges because all entries are defined in the same
file.
This commit fixes this: we can now create individual news entries for
each new entry. A script `create-news-entry.sh` also helps to create it
in the correct format (with the correct filenames and structure).
Having the tests available in the main Nix Flake introduces
unnecessary evaluation for non-developer users and, worse, a
dependency on the nmt library.
Fixes#6354
The `optionsDocBook` function is deprecated in nixpkgs since
nixos-23.11. This commit updates the manual and manpages to
use commonmark formatted documentation instead of the deprecated
docbook format.
