Update README.md

README.md

@@ -67,6 +67,16 @@ To open new terminals on the same container (last container):
 docker exec -it `docker ps -qn 1` /bin/bash
 ```
 
+If you exit from all terminals, the container becomes exited and the previous command won't work, "Container is not running". 
+
+To start the last container again use:
+
+```bash
+docker start -a -i `docker ps -l -q`
+```
+
+This command uses the last created container. To use a different one, substitute the `` `docker ps -l -q` `` with the container ID or name, which can be retrieved with `docker container list -a`
+
 ## Disclaimer
 
 Copyright (C) Institut de Robòtica i Informàtica Industrial, CSIC-UPC.