docs(CHANGELOG): remove html affecting pub.dartlang

![screenshot 2014-01-22 17 02 54](https://f.cloud.github.com/assets/1016365/1980854/63f0b108-83ca-11e3-9eeb-aaa31a928ecc.png)

random html a tag in a markdown file 
http://pub.dartlang.org/packages/angular