Reflect that '@detail_route' responds to GET only by default. (#4582)

docs/tutorial/6-viewsets-and-routers.md

@@ -51,7 +51,7 @@ This time we've used the `ModelViewSet` class in order to get the complete set o
 
 Notice that we've also used the `@detail_route` decorator to create a custom action, named `highlight`.  This decorator can be used to add any custom endpoints that don't fit into the standard `create`/`update`/`delete` style.
 
-Custom actions which use the `@detail_route` decorator will respond to `GET` requests.  We can use the `methods` argument if we wanted an action that responded to `POST` requests.
+Custom actions which use the `@detail_route` decorator will respond to `GET` requests by default.  We can use the `methods` argument if we wanted an action that responded to `POST` requests.
 
 The URLs for custom actions by default depend on the method name itself. If you want to change the way url should be constructed, you can include url_path as a decorator keyword argument.