Update README.md

Author: ajeetraina

workshop/dockerdesktop/README.md

@@ -37,6 +37,8 @@
 
 ## Docker Extensions
 
+
+- [Overview of Docker Extensions](https://github.com/collabnix/dockerlabs/blob/master/workshop/dockerdesktop/mac/extensions/README.md)
 - [RedisInsight Docker Extension](https://github.com/collabnix/dockerlabs/tree/master/workshop/dockerdesktop/mac/extensions/redisinsight/README.md)
 - [Mongo Express Docker Extension](https://github.com/collabnix/dockerlabs/tree/master/workshop/dockerdesktop/mac/extensions/mongo-express/README.md)
 - [Neo4j Docker Extension](https://github.com/collabnix/dockerlabs/tree/master/workshop/dockerdesktop/mac/extensions/neo4j/README.md)