rename options

system/virtualization/virtual-machines/default.nix

@@ -1,4 +1,9 @@
-{ ... }: {
+{ config, lib, ... }: {
+
+    options.sysconfig.virtualization.enable = with lib; mkOption {
+        type = with types; bool;
+        default = false;
+    };
 
     imports = let 
         dir = builtins.readDir ./.;
@@ -7,7 +12,7 @@
         (builtins.attrNames dir)
     );
 
-    config = {
+    config = lib.mkIf config.sysconfig.virtualisation.enable {
         programs.virt-manager.enable = true;
 
         virtualisation.libvirtd.enable = true;