Fix 404

Fixes #417

README.md

@@ -139,7 +139,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 [twitter]: https://twitter.com/_tomchristie
 [0.4]: https://github.com/tomchristie/django-rest-framework/tree/0.4.X
 [sandbox]: http://restframework.herokuapp.com/
-[rest-framework-2-announcement]: topics/rest-framework-2-announcement.md
+[rest-framework-2-announcement]: http://django-rest-framework.org/topics/rest-framework-2-announcement.html
 [2.1.0-notes]: https://groups.google.com/d/topic/django-rest-framework/Vv2M0CMY9bg/discussion
 
 [docs]: http://django-rest-framework.org/