[README] remove the link to the rename announcement

rogerwang · rogerwang · commit f25b28e25233 · 2017-01-16T14:02:47.000+08:00
diff --git a/README.md b/README.md
@@ -3,7 +3,6 @@
 [![Gitter](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/nwjs/nw.js?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)  
 Official site: http://nwjs.io  
 Official documentation: http://docs.nwjs.io/  
-[Announcement](https://groups.google.com/d/msg/nwjs-general/V1FhvfaFIzQ/720xKVd0jNkJ)  
 ## Introduction
 
 NW.js is an app runtime based on `Chromium` and `node.js`. You can 
