Update stale.yml

.github/stale.yml

@@ -19,5 +19,6 @@ markComment: >
   This issue has been automatically marked as stale because it has not had
   recent activity. It will be closed if no further activity occurs. Thank you
   for your contributions.
+
 # Comment to post when closing a stale issue. Set to `false` to disable
-# closeComment: false
+closeComment: true