Publish the project onto flathub

[PolyCatDev]

I've noticed that the project is now also distributed via flatpak bundles. I'm personally willing to try to get the project onto Flathub.

Looking at the manifest it seems to be pretty above board so it will probably just need some rearrangement of the modules to follow flathub's conventions.

The main issue is that I'm not that knowledgeable when it comes to C++ so I'm not be the best person for making patches if need be.

[srcejon]

If you're happy to work on it then cool. If you need help on the c++ side just open an issue and I'll help if I can.

[PolyCatDev]

As an update I still intend on packaging for flathub. It's just that I don't really have the time now due to exams.