Ansible Plugin

Revision ef950c95

Convert to sphinx and majorly reorganize

This introduces a Sphinx docs project and moves almost all of the
content from the README into the sphinx site. After merging, this will
be enabled onto read the docs.

This also reworks the workflows sections significantly and follows the
_snippets approach pioneered in pulp_python.

https://pulp.plan.io/issues/4766
closes #4766