feat: Flake | revamp entire flake (#1)

Reviewed-on: #1

hosts/common/optional/gaming.nix

@@ -0,0 +1,22 @@
+{
+  pkgs,
+  ...
+}:
+
+{
+  programs = {
+    steam = {
+      enable = true;
+      gamescopeSession.enable = true;
+    };
+
+    # to run steam games in game mode, add the following to the game's properties from within steam
+    # gamemoderun %command%
+    gamemode.enable = true;
+  };
+
+  environment.systemPackages = with pkgs; [
+    mangohud
+    protonup-qt
+  ];
+}