restructure system to be toggable

modules/system/nvidia.nix

@@ -1,20 +1,26 @@
 { config, pkgs, lib, ... }:
 
 {
-  # enable nvidia proprietary driver
-  hardware.nvidia = {
-    modesetting.enable = true;  # required
-    open = false;   # use proprietary driver
-    nvidiaSettings = true; # no shit
-    powerManagement.enable = false; # can cause sleep issues
-    package = config.boot.kernelPackages.nvidiaPackages.stable;
+  options = {
+    modules.system.nvidia.enable = lib.mkEnableOption "enables nvidia";
   };
 
-  # install nvidia-smi
-  environment.systemPackages = with pkgs; [
-    nvidia-smi
-  ];
+  config = lib.mkIf config.modules.system.nvidia.enable {
+    # enable nvidia proprietary driver
+    hardware.nvidia = {
+      modesetting.enable = true;  # required
+      open = false;   # use proprietary driver
+      nvidiaSettings = true; # no shit
+      powerManagement.enable = false; # can cause sleep issues
+      package = config.boot.kernelPackages.nvidiaPackages.stable;
+    };
 
-  # enable docker gpu passthrough
-  virtualisation.docker.enableNvidia = true;
+    # install nvidia-smi
+    environment.systemPackages = with pkgs; [
+      nvidia-smi
+    ];
+
+    # enable docker gpu passthrough
+    virtualisation.docker.enableNvidia = true;
+  };
 }