Build and style static get involved page

David added page to home controller and config routes. I'm not sure wy but the highlighted tab is How Gov Works.

This is done, works on mobile and looks the same as Stephen's mock up. No doubt there's somethings that could be changed and improved. If I'm honest, I'm getting tunnel vision with this now and is probably better I submit this pull request now for a second opinion.

https://www.pivotaltracker.com/story/show/44946241