Update stale messages for easier filtering

.github/stale.yml

@@ -33,17 +33,17 @@ staleLabel: stale
 
 # Comment to post when marking as stale. Set to `false` to disable
 markComment: >
-  This issue has been automatically marked as stale because it has not had
+  [STALE_SET] This issue has been automatically marked as stale because it has not had
   recent activity. It will be closed in 14 days if no further activity occurs. Thank you
   for your contributions.
 
 # Comment to post when removing the stale label.
-# unmarkComment: >
-#   Your comment here.
+unmarkComment: >
+  [STALE_CLR] This issue has been removed from the stale queue. Please ensure activity to keep it openin the future.
 
 # Comment to post when closing a stale Issue or Pull Request.
 closeComment: >
-  This stale issue has been automatically closed. Thank you for your contributions.
+  [STALE_DEL] This stale issue has been automatically closed. Thank you for your contributions.
 
 # Limit the number of actions per hour, from 1-30. Default is 30
 limitPerRun: 30