add a line

Author: pscheit

frontend/encore/dev-server.rst

@@ -39,6 +39,7 @@ port 9000 - e.g. http://192.168.1.1:9000.
 If you've activated the :ref:`manifest.json versioning <load-manifest-files>` you need additional configuration to alter the url used in your templates to the ``dev-server``:
 
 .. code-block:: javascript
+    
     Encore
         .setManifestKeyPrefix('build/')