ports/144624: New port: x11-fonts/isabella, Font by John Stracke based on the Isabella Breviary

[Lowell Gilbert]

Can I get some feedback on this port?  I don't care how long it takes to
get committed, but I want to hear whether it's okay before I use it as a
template for a few other fonts.

For some reason, I haven't seen the PR show up on the bugs list, so I'm
not sure whether anybody knew it was there to look at...