Add a Dockerfile for frontend test container; adapt code to simplify synchronization or Docker linkage

README.md

@@ -42,6 +42,14 @@ environment, you can run the following command:
     mysql -u root fic < /var/www/fic-server/db/feed.sql
 
 
+### Frontend container
+
+To run the frontend on the same machine as the backend (but in another
+container), run the following command:
+
+    docker run -P -ti --volumes-from BACKEND_CNTNR_NAME FRONTEND_IMG
+
+
 Production Environnement
 ------------------------