About page HTML

No issue

This is the non-functional, non-Ember markup for the [About page](https://github.com/TryGhost/Ghost-UI/issues/23) from Ghost-UI

Todo items for parts of the UI that need dynamic data are embedded inline. and include:

- Get the version number from the currently running install
- Get the latest version number (and then compare)
- Get details like environment, database & mail
- List the top 20 contributors from the release currently installed & running, looking at both the Ghost & Ghost-UI repos