emacsPackages.evil-markdown: implement passthru.updateScript

pkgs/applications/editors/emacs/elisp-packages/manual-packages/evil-markdown/default.nix

@@ -4,6 +4,7 @@
   fetchFromGitHub,
   markdown-mode,
   melpaBuild,
+  unstableGitUpdater,
 }:
 
 melpaBuild {
@@ -22,6 +23,8 @@ melpaBuild {
     markdown-mode
   ];
 
+  passthru.updateScript = unstableGitUpdater { hardcodeZeroVersion = true; };
+
   meta = {
     homepage = "https://github.com/Somelauw/evil-markdown";
     description = "Integrates Emacs evil and markdown";