Document process for adding things: udev rules

[bsherman]

I think we should have an agreed upon process for adding udev rules our different contributors alway add in a consistent way.

I'm imagining something that fits with what we already do, like ...

How to add new udev rules, order of preference:

use upstream RPM if available; add as packages.json "include" in main
use upstream spec if available, build RPM in COPR; add as packages.json "include" in main
use tarball of upstream git repo if fully dedicated to udev rules; add to confingrepo and build as part of ublue-os-udev-rules
use tarball of upstream git repo, filter to only udev rules(and license, readme, etc); add to confingrepo and build as part of ublue-os-udev-rules
copy udev rule files directly into config repo and build as part of `ublue-os-udev-rules
I think today we already have examples of steps 2, 3, and 5... this PR would be an example of 4.