modularize flatpaks

modules/nix/groups/desktop.nix

@@ -33,6 +33,12 @@ in
       blender.enable = true;
       inkscape.enable = true;
       komikku.enable = true;
+      flatpak = {
+        enable = true;
+        media = true;
+        dev = true;
+        gaming = true;
+      };
     };
   };
 }