Publish to Flathub (follow-up from previous flatpak issue)

[MetalMaxMX]

Hey! I'm very thankful for addressing the issue before regarding flatpaks as I find them to be wonderful. I suppose the last thing I'd want for users of them would be to upload it to the largest repository of flatpaks which is found on https://flathub.org/ both out of convenience and discoverability of the app as flatpak users would be able to find it in there. Alternatively, if you'd prefer setting up your own flatpak repo, that would be valid as well as flatpak's source is open for both client-wise and server-wise implementations so you could do either if you wanted.

Cheers! MetalMaxMX.