Update documentation

[TeaganKing]

Some documentation currently lives here: https://nbscuid.readthedocs.io/en/latest/

It'd be great to update this to reflect newer code structure.

[TeaganKing]

The documentation currently lives here: https://ncar.github.io/CUPiD/index.html

We should also figure out how to directly add the readme file to index.rst (rather than just include hyperlink), as @rmshkv suggested!

[anissa111]

The documentation currently lives here: ncar.github.io/CUPiD/index.html

We should also figure out how to directly add the readme file to index.rst (rather than just include hyperlink), as @rmshkv suggested!

I can take this on!

[TeaganKing]

The documentation for setting up a new notebook that is compatible with CUPiD is now complete, and the readme is now on our documentation page, as well, as mentioned in comments above.

The next item to do would be to focus on including specific function documentation with sphinx and readthedocs.

[TeaganKing]

Additionally, we should add an 'adding scripts' page to the documentation

[mnlevy1981]

Replaced with #73 and #74