add gpg option to home-manager module

home/modules/gpg/default.nix

@@ -0,0 +1,36 @@
+{ config, lib, ... }:
+{
+  options = {
+    youthlic.programs.gpg = {
+      enable = lib.mkOption {
+        type = lib.types.bool;
+        default = true;
+        example = false;
+        description = ''
+          whether enable gpg
+        '';
+      };
+    };
+  };
+  config =
+    let
+      cfg = config.youthlic.programs.gpg;
+    in
+    lib.mkIf cfg.enable {
+      services.gpg-agent = {
+        enable = true;
+        enableSshSupport = true;
+      };
+      programs.gpg = {
+        enable = true;
+        mutableKeys = true;
+        mutableTrust = true;
+        publicKeys = [
+          {
+            source = ./public-key.txt;
+            trust = "ultimate";
+          }
+        ];
+      };
+    };
+}