added video-compare to arch linux AUR

[codeliger]

I added video-compare to the AUR: https://aur.archlinux.org/packages/video-compare

Please comment if there are any problems building/installing

[jonfryd]

Thanks for your contribution, @codeliger!

[jonfryd]

Hey, @codeliger!

I don't use Arch Linux myself, but I would love to include instructions in the README.md (as an extension to the HomeBrew instructions we have added today) for how to install video-compare via the command line.

Could you provide a PR when time permits, please?

Cheers!