[Fedora-packaging] Documentation on request special rawhide tags

[Bruno Wolff III]

I went looking for documentation on when and how to request special
dist tags for rawhide to make soname bumps less disruptive and didn't
find any official process documentation for packagers.

I ended up just filing a releng ticket, which will probably do what I want.
But I think there is a problem. Either the documention is harder to find
than it should be or there isn't any. I did find something for tagging in
new rawhide packages, but that isn't quite the same thing. My knowledge
that you can make such requests came from email messages I have seen on
the mailing lists.