fixed api_view decorator useage

docs/api-guide/parsers.md

@@ -37,7 +37,7 @@ You can also set the renderers used for an individual view, using the `APIView`
 
 Or, if you're using the `@api_view` decorator with function based views.
 
-    @api_view(('POST',)),
+    @api_view(['POST'])
     @parser_classes((YAMLParser,))
     def example_view(request, format=None):
         """