Update to EXTRA_ORM.md to correct config key

docs/EXTRAS_ORM.md

@@ -60,7 +60,7 @@ key in you configuration file:
 return array(
     'doctrine' => array(
         'configuration' => array(
-            'my_dbal_default' => array(
+            'orm_default' => array(
                 'types' => array(
                     // You can override a default type
                     'date' => 'My\DBAL\Types\DateType',
@@ -113,4 +113,4 @@ return array(
 
 Now using Schema-Tool, whenever it detects a column having the "tinyint" it will convert it into a "tinyint"
 Doctrine Type instance for Schema representation. Keep in mind that you can easily produce clashes this 
-way, each database type can only map to exactly one Doctrine mapping type.
+way, each database type can only map to exactly one Doctrine mapping type.