Finally switch to flakes.

home-manager/guiapps/mangohud.nix

@@ -0,0 +1,32 @@
+{pkgs, ...}: {
+  home = {
+    packages = with pkgs; [
+      mangohud
+    ];
+    file = let 
+      # Mangohud config file
+      mangoConf = ''
+        table_columns=2
+        frametime=0
+        legacy_layout=0
+        font_scale=0.80
+        background_alpha=0.25
+        
+        # Set the loads and such
+        exec=echo $(echo $XDG_CURRENT_DESKTOP | sed 's/./\U&/') on $(cat /etc/os-release | grep PRETTY_NAME | cut -d '"' -f 2)
+        fps
+        fps_color_change
+        ram
+        vram
+        cpu_stats
+        cpu_load_change
+        gpu_stats
+        gpu_load_change
+        frame_timing
+      '';
+    in {
+      # Mangohud config
+      ".config/MangoHud/MangoHud.conf".text = mangoConf;
+    };
+  };
+}