Sphinx documentation

[bmtgoncalves]

Now that integration with readthedocs is complete, we have to start populating the documentation. There are a few specific things that we should add:

• Brief overview of the structure of the library
• High level description of the three main modules
• Explanation of the arguments for each method
• Examples of the way to use the package. We can refer to the blog posts for examples of the full functionality

With some luck, the documentation can also serve as the starting point for defining a complete set of tests