Need high-level docs. #41

Hi @astroplanners/astroplanners-contributors,

I'm starting to write the docs and would like some input for what you would like to see/not see.

My starting point is to take the current RTD site and add:

• A Tutorials page with separate pages for a few different use cases.
• Getting Started would have a section explaining how the different types of objects correspond to observing concepts (e.g., target info contained in a Target object, etc.) and the way that you extract attributes/use methods in general. Perhaps also a section for basic tasks (such as creating Observer and Target objects).
• A How to.. page linking to others that explain how to do specific things (e.g., extract alt/az info).
• A Plots/Visualization page containing basic examples and linking to a detailed run-through of all the options for each plotting function.