Getting started

PT story https://www.pivotaltracker.com/story/show/74918112

Adding static_page for Getting_started guide
Adding links to the guide to the landing page Let's Code, Navigation bar, Welcome email

responsiveness issue, the link goes missing at a certain width (before the navbar collapses):
![missing_getting_started](https://cloud.githubusercontent.com/assets/2663402/3606683/f3986f00-0d39-11e4-9e1a-6d074a7ba49e.png)