Add flatpak support

[kelbazz]

Description

Flatpak is a good format to make an application available for most distros.

How to do it

• A json or yaml manifest file
• Some icon and symbolic
• A .desktop entry

[m-obeid]

This was already planned, the only thing we’re missing is an app icon

[atmaxinger]

I opened #9 for initial flatpak support 🙂

[m-obeid]

Hello, anyone can help me figure out what's wrong?

For some reason, on Flatpak specifically, the playback stops after around 5 seconds. Seeking does make it play again but itll stop soon after again.