old game in NixOS

an old game abandoned by creators no longer work on the more moderate versions of debian or ubuntu and neither those with wayland, so I made a corrected appimage, now I brought NixOS because I did not find it in pkgs nix, if you are interested have here: [https://github.com/tehnium/xgammon-nix](https://github.com/tehnium/xgammon-nix)