add examples to docs page

This adds some quick example links to the docs page, including the TodoMVC app & gcloud-keystore -- let me know if I forgot anything!

![screen shot 2014-11-10 at 1 55 29 pm](https://cloud.githubusercontent.com/assets/723048/4981663/2b09f4a4-690b-11e4-9c45-397a35a1694b.png)