NM in the initrd for Fedora CoreOS

["Colin Walters" <walters verbum org>]

I was trying out the current F31 dracut network-manager module, and couldn't get it to do anything useful.
See: https://github.com/coreos/fedora-coreos-config/pull/259

If anyone has a bit of time to help out that'd be appreciated!

One higher level architectural question; why is the NM initrd code structured as "run once and quit" rather 
than running as a systemd unit, same way as the main OS, and default to having the switchroot stop the 
service?