Add cmd to execute mongo via docker

Author: fabiofdsantos

README.md

@@ -79,6 +79,7 @@ mongod
 
 If you have docker installed
 ```bash
+docker run -d -p 27017:27017 mongo
 docker run -d -p 1113:1113 -p 2113:2113 eventstore/eventstore
 docker run -d -p 6379:6379 redis
 ```