Fix markdown formatted link inside inline html

The `/codelab/setup.md` file contained a markdown-flavored link inside of embedded html, which resulted in this: 
![screenshot 2014-11-04 20 23 28](https://cloud.githubusercontent.com/assets/6025224/4906441/eb7f7662-6458-11e4-8eb0-5aab157c8cb9.png)


From http://daringfireball.net/projects/markdown/syntax#html:

> Note that Markdown formatting syntax is not processed within block-level HTML tags. E.g., you can’t use Markdown-style emphasis inside an HTML block.