Fix doc

Author: mcg-web

README.md

@@ -23,6 +23,7 @@ Browse your version documentation:
 * [0.11 (STABLE)](https://github.com/overblog/GraphQLBundle/blob/0.11/README.md)
 * [0.12 (STABLE)](https://github.com/overblog/GraphQLBundle/blob/0.12/README.md)
 * [0.13 (DEV)](https://github.com/overblog/GraphQLBundle/blob/master/README.md)
+
 [Versions requirements](docs/index.md#versions-requirements)
 
 Documentation