[EPIC] Use nbsphinx to integrate Jupyter notebooks with Sphinx documentation

[chmreid]

In order to address #75 (repository is missing quickstart instructions), the data-consumer-vignettes repo needs the Jyupyter notebooks to be readable and presentable automatically, without needing to manually populate a table of contents, readmes for each project, etc.

Toward this end, we propose using nbsphinx to automatically turn Jupyter notebooks into Sphinx documentation pages. This will help with making the vignette notebooks more consistent, and will make writing quickstart instructions a lot easier.