Partially flesh out the readme

Rename readme from "README.md" to "README.rst". reStructuredText is the standard
markup format for Python projects, and this project is primarily Python.

The readme is not fully fleshed out. However, it contains much useful
information, and it should be enough to get a developer up and running with the
project in its current state.
Add config file for the "epydoc" program.

epydoc is used to generate API docs from code. Add a config file that customizes
the output that epydocrc generates. Remove the `.gitkeep` file in the "configs"
folder, as the "configs" folder is no longer empty, and it should never be
empty.