add steam module

sadly this has to be a system package until we find a non shitty way of
installing in through hm

nixos/steam.nix

@@ -19,12 +19,13 @@ in {
     };
 
     environment = {
-      systemPackages = with pkgs; [
-        protontricks
-        protonup
-        protonup-ng
-        winetricks
-      ];
+      systemPackages = with pkgs;
+        [
+          protontricks
+          protonup
+          protonup-ng
+          winetricks
+        ];
     };
   };
 }