First pass at public gocraft/web site.

- Leveraged Poole's theme (https://github.com/poole/www)
- Pygments + GitHub syntax highlighting
- Copied some initial examples from the existing README to provide
  content

- Added some additional margin below h1,h2,h3 tags.
- Brought more content over from the README.

Fixed asset URLs.

Fixed baseurl behaviour.

Changed syntax to "tomorrow" to improve contrast.