Add link

news/2016-03-08-announcing-2-1-3.md

@@ -14,7 +14,7 @@ option has been broken since 2.1.0. That's fixed now, and should help
 to improve compute-bound benchmark results.
 
 One other minor change worth noting is the addition of two functions
-to the `immutant.web.undertow` namespace: `http-handler`, which turns
+to the [immutant.web.undertow] namespace: `http-handler`, which turns
 a Ring handler into an [Undertow] `HttpHandler`, and
 `graceful-shutdown`, which invokes Undertow's ability to gracefully
 shutdown a web server by prohibiting new requests while pending ones
@@ -63,3 +63,4 @@ Immutant, you can always find us on
 [Quartz]: http://quartz-scheduler.org/
 [Narayana]: http://www.jboss.org/narayana
 [Feature Demo]: https://github.com/immutant/feature-demo
+[immutant.web.undertow]: /documentation/2.1.3/apidoc/immutant.web.undertow.html