New Gist functionality goals (GitHubMode/GistHubMode)

I spent some time working on the new GistHub mode page, I warmed up my HTML5 knowledge and made a page that came surprisingly close for just less than 35 minutes of work.

The page is in early Alpha testing and is not functional in several areas. Features like saving files, line counts, colored syntax, analytics. sharing, other Gist viewing and the general page layout. are currently not available.

These features will need to get implemented. I don't have the time and knowledge to do it myself at the moment. Contributors are welcome to help, as long as the CONTRIBUTING.md rules are followed.