[389-devel] Please review: Issue #77 - Add sphinx documentation

[Simon Pichugin]

Hi team,
Most of the comments were applied. Thanks!

Now the layout is:
- index.rst - welcoming word, Table of Contents and Contact Us.
- guidelines.rst - is included into index.rst and contains basic test
  development workflow, pytest features overview, and basic lib389 and
  python-ldap features.
- replica.rst, agreement.rst, aci.rst, etc. - each contains the
  respective documentation.

Currently I do add docstrings to lib389 and rst files with
references. It will be the next patch.
Now, please, check if you agree with the existing format.

The generated example - https://fedorapeople.org/~spichugi/html/

https://pagure.io/lib389/issue/raw/files/95c83274b06e9b48993af02040a23194...

https://pagure.io/lib389/issue/77

Thanks,
Simon