Update the cookbook plugin

This adds the change:

- Add example of extending Gerrit's top menu item

Change-Id: Ia28dc6622732655411eaed84e4147c35b909a96f
diff --git a/plugins/cookbook-plugin b/plugins/cookbook-plugin
index b31cee7..5ee3f28 160000
--- a/plugins/cookbook-plugin
+++ b/plugins/cookbook-plugin
@@ -1 +1 @@
-Subproject commit b31cee76e19d30e8b6bda41af5a15ab5f7668b97
+Subproject commit 5ee3f28739700e97b91231a2b694f3ba78065e86