add alias tip for dockercontainer

Setup/README.md

@@ -91,7 +91,11 @@ From anywhere in the command line you can start the docker container by running
 
     docker start LDD-TPR-fenics2019 & docker exec -ti -u fenics LDD-TPR-fenics2019 /bin/bash -l
 >>>
-Tip: This command should be stored as a script or alias to not have to remember it.
+Tip: This command should be stored as a script or alias to not have to remember it. For example, you could add
+~~~bash
+alias LDDdocker='docker start LDD-TPR-fenics2019 & docker exec -ti -u fenics LDD-TPR-fenics2019 /bin/bash -l'
+~~~
+to your ~/.bashrc file (outside of the Docker container).
 >>>
 You should see a welcome message greeting you
 ```