Update creating_an_admin.rst

Resources/doc/getting_started/creating_an_admin.rst

@@ -15,7 +15,7 @@ using these commands:
 .. code-block:: bash
 
     $ php app/console doctrine:generate:entity --entity="AppBundle:Category" --fields="name:string(255)" --no-interaction
-    $ php app/console doctrine:generate:entity --entity="AppBundle:BlogPost" --fields="title:string(255) body:textdraft:boolean" --no-interaction
+    $ php app/console doctrine:generate:entity --entity="AppBundle:BlogPost" --fields="title:string(255) body:text draft:boolean" --no-interaction
 
 After this, you'll need to tweak the entities a bit: