feat: add nixosModule template

hosts/common.nix

@@ -2,6 +2,7 @@
 {
   imports =
     [
+      ../nixosModules
       ../configs/boot.nix
       ../configs/nix-config.nix
       ../configs/security.nix
@@ -13,4 +14,5 @@
     ++ lib.optionals (type == "graphical") [
       ../configs/graphical.nix
     ];
+  nixosModules.enable = true;
 }

nixosModules/default.nix

@@ -0,0 +1,23 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+let
+  moduleName = "nixosModules";
+  cfg = config."${moduleName}";
+in
+{
+  imports = [
+    # The rest
+  ];
+
+  options = {
+    "${moduleName}".enable = lib.mkEnableOption "Enable ${moduleName}.";
+  };
+
+  config = lib.mkIf cfg.enable {
+    environment.systemPackages = with pkgs; [ micro ];
+  };
+}