Create documentation on using the microphone

[andrewg23]

Documentation on how to set up and interact with the microphone will be useful in helping others learn how to use the microphone. This documentation will include instructions along with example code.

[andrewg23]

I created the setup.md file in microphone/ with some basic instructions on setting up the microphone.

[amalaquias]

Edited readme and added new notebooks to test the audio capabilities of the nano with python using a virtual environment. I'm not sure how much more testing we have to do with the microphone.