Ship an AppStream/Metainfo file

[corsac-s]

Hi,
while doing the initial packaging work for Debian, I was reminded it could be nice to provide an AppStream/Metainfo file describing the hardware supported by libirecovery due to the presence of an udev rule (I think same thing could be done for usbmuxd).

Some pointers I was given:

• https://wiki.debian.org/USB/GadgetSetup
• https://wiki.debian.org/AppStream/Guidelines#Announcing_supported_hardware
• https://www.freedesktop.org/software/appstream/docs/chap-Quickstart.html

Attached is an file I quickly crafted for Debian, but the the ID should be shared, it would really make sense to include it upstream (obviously feel free to tune the wording and even the license)
org.libimobiledevice.libirecovery.metainfo.xml.txt

The file should be put in /usr/share/metainfo.