docs: fixed missing migration step that would make sure proper permissions are set on filesystem

docs/source/migration/migration-to-docker.rst

@@ -234,7 +234,6 b' Once that is done, we can now move from the host directory into docker storage e'
 
     root@a27697d13f44:/vol# mv /vol/backupvolume/repos/* /vol/repovolume/
 
-
 7.5. Move gists
 
 .. code-block:: bash
@@ -247,6 +246,12 b' Once that is done, we can now move from the host directory into docker storage e'
 
     root@a27697d13f44:/vol# mv /vol/backupvolume/repos/* /vol/repovolume/
 
+7.7 Make sure proper permissions are set on the storage files, group/user is 999
+
+.. code-block:: bash
+
+    root@a27697d13f44:/vol# chown -R 999:999 /vol/repovolume
+
 
 8. Ensure other old services are stopped
 ++++++++++++++++++++++++++++++++++++++++