feat: add initial modules

modules/nixos/yubikey.nix

@@ -0,0 +1,23 @@
+{
+  pkgs,
+  lib,
+  config,
+  ...
+}:
+{
+
+  options = {
+    yubikey = {
+      enable = lib.mkEnableOption "enable yubikey module";
+    };
+  };
+
+  config = lib.mkIf config.yubikey.enable {
+    environment.systemPackages = with pkgs; [
+      yubikey-personalization
+      yubikey-manager
+    ];
+
+    services.pcscd.enable = true;
+  };
+}