adds nvtop for all hosts

config/nixos/hardware/mennos-laptop.nix

@@ -19,6 +19,12 @@
   # Load nvidia driver for Xorg and Wayland
   services.xserver.videoDrivers = [ "nvidia" ];
 
+  # nvtop, a system monitor for GPUs
+  environment.systemPackages = with pkgs; [
+    nvtopPackages.nvidia
+    nvtopPackages.amd
+  ];
+
   hardware.nvidia = {
     # Modesetting is required.
     modesetting.enable = true;