Change Title to Generic Reference

This commit will change the title from Model-Registry-db mysql:8.3.0 to use a generic title which will reflect that pull image rate limiting is not confined to mysql:8.3.0

Co-authored-by: Matteo Mortari <[email protected]>

README.md

@@ -134,7 +134,7 @@ End-to-end testing is developed with Robot Framework; this higher-lever layer of
 directly checking the end results in the backend gRPC MLMD server.
 
 ## Tips
-### Model-Registry-db mysql:8.3.0 rate limiting
+### Pull image rate limiting
 
 Ocassionally you may encounter an 'ImagePullBackOff' error within the model-registry-db container. See example below.