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

what you did here: https://github.com/AgileVentures/WebsiteOne/pull/470/files#diff-bd5fbcdc8c1d642e80e90ed8b43fb1b5R64