bundlerUpdateScript: init and use (#64822)

pkgs/development/tools/misc/mdl/.bundle/config

@@ -1,3 +0,0 @@
----
-BUNDLE_PATH: "vendor/bundle"
-BUNDLE_CACHE_ALL: "true"

pkgs/development/tools/misc/mdl/default.nix

@@ -1,15 +1,17 @@
-{ lib, bundlerApp }:
+{ lib, bundlerApp, bundlerUpdateScript }:
 
 bundlerApp {
   pname = "mdl";
   gemdir = ./.;
   exes = [ "mdl" ];
 
+  passthru.updateScript = bundlerUpdateScript "mdl";
+
   meta = with lib; {
     description = "A tool to check markdown files and flag style issues";
     homepage = https://github.com/markdownlint/markdownlint;
     license = licenses.mit;
-    maintainers = with maintainers; [ gerschtli manveru ];
+    maintainers = with maintainers; [ gerschtli manveru nicknovitski ];
     platforms = platforms.all;
   };
 }