Added missing code example in the RM command reference of command to delete all stopped containers
@@ -1661,6 +1661,8 @@ containers removing all network communication.
The main process inside the container referenced under the link `/redis` will receive
`SIGKILL`, then the container will be removed.
+ $ docker rm $(docker ps -a -q)
+
This command will delete all stopped containers. The command `docker ps
-a -q` will return all existing container IDs and pass them to the `rm`
command which will delete them. Any running containers will not be
