Make Freegemas easier to package

[sharkwouter]

I was contacted by email by the creator of a Freegemas package for OpenSUSE, which can be found here: https://build.opensuse.org/package/show/home:mnhauke:games/freegemas

While packaging I found some minor things that might be useful:

1. make a release (git tag) so I don't have to package a random snapshot

2. read the gamedata (folder media/) from a systemwide installation path and not only from ./media/ relative to the binary location I actually workaround that issue with an ugly wrapper script

3. provide a .desktop file so Linux users have a nice entry in their app-menu.

4. provide a game icons (ideally in a scalable SVG) the .ico file is not ideal

I agree with him that some additional work should be put in to make packaging easier. I'd say the following actions should be taken:

• [x] Allow setting the location for assets when building
• [x] Make a release

The desktop file and icon he mentions would be nice as well, but slightly less mandatory.

[sharkwouter]

The 22.02 release is currently being build by the GitHub CI and will release automatically when done.