Update CACHING.md

Co-authored-by: Bishal Prasad <bishal-pdmsft@github.com>

CACHING.md

@@ -64,7 +64,7 @@ In case of workflows with matrix running for multiple Operating Systems, the cac
 
 ### Limiting cache to only the current workflow/attempt
 
-Caches scoped to the particular workflow run id or run attempt can be stored and referred by using the run id/attempt
+Caches scoped to the particular workflow run id or run attempt can be stored and referred by using the run id/attempt. This is an effective way to have a short lived cache.
 
 ```yaml
     key: cache-${{ github.run_id }}-${{ github.run_attempt }}