Add basic AppStream metainfo data

[Conan-Kudo]

For packaging the Red Hat fonts in Linux distributions (such as Fedora),
AppStream metadata is required to support discoverability and installability
through modern software centers like GNOME Software and Plasma Discover.

This adds the most basic data for supporting that, which can be fleshed
out more over time as needed.

[Conan-Kudo]

This is being used for the Fedora and EPEL packaging for the Red Hat fonts, by the way.

[Conan-Kudo]

ping?

[Conan-Kudo]

ping?

[starryeyez024]

Hi @Conan-Kudo - thank you for submitting this MR. I've notified the appropriate folks who need to review it.

[starryeyez024]

Adding information from the email thread:

I'd now be inclined not to use a special metadata license and to assume that OFL 1.1 covers font metadata well enough. This is mainly because of my lingering concerns around the use of "Red Hat" as the name of these fonts (and even though the CC licenses are clear that they do not license trademark rights).

@richardfontana please add further details here as necessary, thanks!

[Conan-Kudo]

There's a limited number of metadata licenses accepted by the AppStream spec today, mostly CC licenses. I've typically used CC-BY-SA for my metadata licenses for metainfo files, because it's a good default for that and does handle trademarks appropriately.

[funnelfiasco]

@richardfontana is CC BY-SA acceptable for the metadata given @Conan-Kudo's comment?

[richardfontana]

@funnelfiasco @Conan-Kudo @starryeyez024 Yes this is fine. Thanks!

[Conan-Kudo]

@starryeyez024 Can we get it merged now?

[Conan-Kudo]

@starryeyez024 Thanks for merging it!