Edit Python overview

[willingc]

Closes #143.

Addresses #81.

• Correct Python errors and inaccuracies.
• Update style to be consistent with Python docs and PEP8
• Add a tip addressing functions for Expand overview of functions in 01-short-introduction-to-Python #143

[tracykteal]

Thanks, this is terrific! Besides having this in Setup, I think it would be good to have some of that where instructors knew to go through it during the workshop.

Maybe we can leave that PR as is, and either some of it can be added to 'intro to Python' at the very beginning, or it could be its own episode, and it could be the first one taught, so 00-intro-to-jupyter-notebook? (I'd just have to figure out what happens if you have more than one 00 lesson on ordering.)

[willingc]

Let's merge and then do a separate issue that reorganizes the way you would like it.

[wrightaprilm]

I would prefer to merge this as is and do reorganization later, if need be. I'm catching up on PRs now - are all the lessons getting 00-level intros to the tools used (Jupyter notebook, rstudio, whatever SQL does)?

[wrightaprilm]

Reads well; great work. Merging now.

[willingc]

Thanks @wrightaprilm. Happy to help.