Temporary HTML for the User Management screen & Setup screen

No reference

- Move Setup screen HTML from [Ghost-UI](https://github.com/TryGhost/Ghost-UI/blob/master/setup.html) to here, written by @johnonolan
- HTML for the User Management screen [Ghost-UI#21](https://github.com/TryGhost/Ghost-UI/issues/21)

Both files here are not functional & not built in Ember, it serves as a guide of to how to structure the HTML so it relates to the corresponding CSS correctly.