update develop installation instructions

odoo_scripts/docker_dev_start.py

@@ -713,7 +713,7 @@ def main(argv=None):  # IGNORE:C0111
             "/opt/odoo/data",
         ]
     else:
-        extra_volumes = []
+        extra_volumes = ["/var/lib/odoo"]
     for extra_volume in extra_volumes:
         volume_name = "{}_{}".format(project_name, extra_volume.replace("/", "_"))
         DockerClient.create_volume(