Python package should have Sphinx infra set up

[jameslamb]

The Python package uses Sphinx docstrings and we declare various sphinx packages in setup.py, but none of the actual infra (like a conf.py) to run the docs is set up.

Closing this issue involves walking through sphinx-quickstart (here)

[csyhuang]

[HacktoberFest] I'm interested to take this issue.

The corresponding pull request: https://github.com/UptakeOpenSource/uptasticsearch/pull/130