readme: rename to rst

refs #23
readme: Only relavent information

A link to our docs should be included once up on readthedocs or elsewhere.
The readme should link to specific sections within the docs, including setup,
running, and maybe other maintenance tasks like migrations as well.

refs #23
readme: instruct building of docs

refs #23
Merge pull request #38 from orvsd/readme_restructure_text

Gut the readme.
Merging because this can't break anything.