Set up the website for documenation

[agbeltran]

Previous documentation at: http://wg3-metadataspecifications.readthedocs.io/

Move it github pages and add json documenter.

[agbeltran]

Consider:
https://daler.github.io/sphinxdoc-test/includeme.html
https://github.com/Syntaf/travis-sphinx

[agbeltran]

Consider including both schemas and context files.

[agbeltran]

Documentation including schemas available at http://datatagsuite.github.io/docs/html/

Leaving issue open so that we add the context files to the documentation.