Since with the completion of the docbook migration) it seems unclear
what relevance editing xml in generall and docbook in particular with
Emacs still has to NixOS at all, and people interested in the topic
will presumably look to other resources elsewhere (e.g. to the nXML
mode's actual documenation).
Apart from being bad practice, absolute paths may be confusing;
especially the `services.emacs.package` definition in the "Running
Emacs as a service" section. Remove them.
Supersedes: https://github.com/NixOS/nixpkgs/pull/192019
Co-authored-by: Alexander Bantyev <balsoft@balsoft.ru>
these examples were turned into untitle anchors previously because at
the time supporting examples was not deemed necessary or useful. now
that we have them we can restore them though.
