many improvements

modules/nixos/user.nix

@@ -0,0 +1,27 @@
+{
+  lib,
+  config,
+  ...
+}:
+let
+  cfg = config.nix-config;
+in
+{
+  options = {
+    nix-config.userName = lib.mkOption {
+      type = lib.types.str;
+      default = "remy";
+      };
+  };
+
+  config = {
+
+    users.users.${cfg.userName} = {
+      isNormalUser = true;
+      extraGroups = [
+        "wheel" # Enable ‘sudo’ for the user.
+        # other groups are added as needed, eg. networkmanager
+      ];
+    };
+  };
+}