{Issue #6}: Add sphinx docs

[JoseALermaIII]

Description of new feature, or changes

Initializes documentation using Sphinx. Supports both reStructuredText and markdown. Content is mainly from docstrings via autodoc and a rewrite of README.md to reStructuredText format. Also added FAQ page that includes mention of Windows compatible spinners. Specifically, that it defaults to line for now. Compatibility with other operating systems can be added as needed.

Checklist

• Your branch is up-to-date with the base branch
• You've included at least one test if this is a new feature
• All tests are passing

Related Issues and Discussions

Fixes #6 and finishes off #5.

Proofing may be needed to ensure all the desired information is present. For example, in docs/source/conf.py I set copyright = '2019, Manraj Singh' rather than copyright = '2019, Manraj Singh and contributors'.

Directions for building documentation included in DEVELOPMENT.md.

Documentation can be tested with tox -e sphinx.

People to notify

@manrajgrover

[JoseALermaIII]

The napoleon extension is needed because of the NumPy style docstrings.
Edit: Sample website of latest commit can be found at halo.josealerma.com

[JoseALermaIII]

autodoc writes the API reference from the docstrings, so I didn't replicate the API section from README.md.

Docs seem sparse. Should CONTRIBUTING.md be added?

[coveralls]

Pull Request Test Coverage Report for Build 413

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-1.5%) to 89.563%

---

Totals
Change from base Build 409:	-1.5%
Covered Lines:	900
Relevant Lines:	990

---

💛 - Coveralls

[JoseALermaIII]

After comparing the API section in README.md, I'd like to replace the docstrings with it since it is much more detailed.

I'll work on that next so that the API section is no longer necessary.

[JoseALermaIII]

It will be challenging to update the version information in two places, so here are a few ways to single-source the package version.

For simplicity, I usually put it in the module's __init__.py, like __author__ and __email__ are, as __version__:

halo/halo/__init__.py

Lines 1 to 3 in f76b256

	# -*- coding: utf-8 -*-
	__author__ = 'Manraj Singh'
	__email__ = 'manrajsinghgrover@gmail.com'

Not sure what the best practice is, but I'm willing to try them out.