clash-verge: add update script

pkgs/by-name/cl/clash-verge/package.nix

@@ -9,6 +9,7 @@
 , webkitgtk
 , udev
 , libayatana-appindicator
+, nix-update-script
 }:
 
 stdenv.mkDerivation rec {
@@ -51,6 +52,8 @@ stdenv.mkDerivation rec {
     ln -sf ${lib.getExe clash-meta} $out/bin/${clash-meta.meta.mainProgram}
   '';
 
+  passthru.updateScript = nix-update-script { };
+
   meta = with lib; {
     description = "A Clash GUI based on tauri";
     homepage = "https://github.com/zzzgydi/clash-verge";