More doc

Readme.md

@@ -7,7 +7,14 @@ git clone https://gitlab.tetras-libre.fr/tetras-libre/pretty-noemie-cms-docker
 cd pretty-noemie-cms-docker
 cp .env.sample .env
 docker-compose up
-ln -s /var/lib/docker/volume/prettynoemie_sites/_data/ sites
+mount -o bind /var/lib/docker/volume/prettynoemie_sites/_data/ sites
+```
+
+**Note**
+
+To make the bind mount permanent, use a fsta line like :
+```fstab
+/var/lib/docker/volume/prettynoemie_sites/_data/ /path/to/sites none defaults,bind 0 2
 ```
 
 ## Add a site