Adding upd.dev to skills sources

[xlab]

Hello! Awesome idea and implementation, Google already suggests to use this:

I'm creator of upd.dev.
I was going to ask if it's possible to add alternative git sources, e.g. I have https://upd.dev/skills that mirrors a lot of various skills sources, how about

uvx skill-add upd.dev/skills/foo

# -- or --

uvx skill-add upd.dev/someone/foobar

Anything that is https://upd.dev/skills/foo.git is a valid Git clone-able repo.