khard: add module

tests/modules/programs/khard/basic_config.nix

@@ -0,0 +1,34 @@
+{
+  accounts.contact = {
+    basePath = ".contacts";
+    accounts.test = {
+      local.type = "filesystem";
+      khard.enable = true;
+    };
+  };
+
+  programs.khard = {
+    enable = true;
+    settings = {
+      general = {
+        default_action = "list";
+        editor = [ "vim" "-i" "NONE" ];
+      };
+
+      "contact table" = {
+        group_by_address_book = true;
+        reverse = false;
+        preferred_phone_number_type = [ "pref" "cell" "home" ];
+        preferred_email_address_type = [ "pref" "work" "home" ];
+      };
+    };
+  };
+
+  test.stubs.khard = { };
+
+  nmt.script = ''
+    assertFileContent \
+      home-files/.config/khard/khard.conf \
+      ${./basic_config_expected}
+  '';
+}