I’ve just created the Friulian keyboard layout. I don’t know your policy about languages, but I’ll be happy to share it. I’m the friulian translator and coordinator in GNOME, Fedora and other translation projects. I can help if needed.
Hi! We’re definitely interested! You can submit your changes at https://review.haiku-os.org via git.
@kallisti5 is correct for the keyboard layout; but translations must go through i18n.haiku-os.org. We can get you set up as a Language Manager for Friulian on those services if you’d like so that you can translate Haiku, too.