📝 Update the README for SQL directory

Signed-off-by: mathieu.brunot <mathieu.brunot@monogramm.io>

ecs/README.md

@@ -105,6 +105,7 @@ Here are the volume you may want to map:
 - /home/ejabberd/logs/: Directory containing log files
 - /home/ejabberd/database/: Directory containing Mnesia database. You should back up or export the content of the directory to persistent storage (host storage, local storage, any storage plugin)
 - /home/ejabberd/conf/: Directory containing configuration and certificates
+- /usr/src/ejabberd/sql: Directory containing SQL install scripts
 
 All these files are owned by ejabberd user inside the container. Corresponding
 UID:GID is 9000:9000. If you prefer bind mounts instead of docker volumes, then