Add more explicit steps to the Getting Started example

[willingc]

Improve the Getting Started section of the docs.

Right now it's easy to miss that two files are needed: a notebook (.ipynb file) to test and a test file (.py file) to write the tests.

It would also be helpful to add an explicit step on how to run the test file.

[mmoralls]

Hello! I'm new to contributing and looking for something to work on. It looks like there hasn't been any progress as there isn't a Getting Started section.

[MSeal]

Hello @mmoralls, the initial work on the project was mostly through Google Summer of Code, but it's had attention and improvements since then. We're outlining a range of issues for new contributors, especially with the PyLadies mentored sprint coming up this weekend. Tickets like this are to lower friction points for new contributors but it's certainly not a blocker to work on the project!