Update routers.md

Author: Rohit10jr

docs/api-guide/routers.md

@@ -352,5 +352,4 @@ The [`DRF-extensions` package][drf-extensions] provides [routers][drf-extensions
 [drf-extensions-customizable-endpoint-names]: https://chibisov.github.io/drf-extensions/docs/#controller-endpoint-name
 [url-namespace-docs]: https://docs.djangoproject.com/en/stable/topics/http/urls/#url-namespaces
 [include-api-reference]: https://docs.djangoproject.com/en/stable/ref/urls/#include
-[simplified-routing-release-note]: https://docs.djangoproject.com/en/stable/releases/2.0/#simplified-url-routing-syntax
 [path-converters-topic-reference]: https://docs.djangoproject.com/en/stable/topics/http/urls/#path-converters