Updating the Flatpak Thrive description

@Buckly pointed out that the Flatpak description is not optimal (and there’s a duplicate screenshots).

All of that can be modified by making a pull request to modify this file:

As I have a ton of stuff to do (like always; I just installed a new music bot) I’d really appreciate if someone else could take the time to fix that file.

I opened an issue so this isn’t completely forgotten about: