Simple local report rendering

[bmtcril]

Description:

Finishes the ancient implementation of human readable reporting in rst and html. This should allow people to get a readable report from any well-configured annotation output without having to deal with Sphinx.

Closes: #128

Testing instructions:

1. Create a code-annotations in any of the usual ways or use the one here: https://gist.github.com/bmtcril/0441b96e8cc92ba0c24b3178c4ef8e00
2. See if the instructions in the getting_started and configuration docs are sufficient to help you configure and run the generate_docs command. A config that works with the gist above is included in that gist.
3. Try viewing rst documents using restview (linked in the docs)
4. Try viewing html document using a browser

Docs generate cleanly, should not throw errors when viewed, and should be relatively easy to follow. Links to github should work if configured.

restview screenshots:

HTML screenshots:

[saraburns1]

LGTM!