A first draft of the bluebuttonjs.com site without placeholder text / a warning that the site is in development

@blacktm I'd love to get www.bluebuttonjs.com to a place where it can advertise the project for us, and I had some time on an airplane this weekend. Can you check it out and let me know if there's anything you want to change?

The main page to look at is probably the home page, to make sure it represents what you want about the project. I also pulled out the News page, because it seems unlikely we'll actually be able to keep it updated / interesting and copied over the documentation from the main project / expanded it a fair bit (I might change the main project to just point to this documentation page after we push this).
Jekyll told me our old setting was deprecated