TODO after July 2020 course

• adjust/remove teaching/exercises timing estimates for each episode
• add more explanation/demonstration of the use of yield, maybe side-by-side comparison of a definition with return vs yield
• provide more info about sets and their methods
• add "How to Jupyter" page to Extras
• annotate code blocks in solutions more often?
• make heading levels consistent between chapters
• add "glossary" section to end of each chapter
• add section to Setup with link to download all data
• align keypoints with content in 01-syntax
• add more explanation to/re-work exercise 4.2
• mention action parameter for argparse arguments
• add example of where argparse won't catch problems with user input e.g. file doesn't exist, numbers that must be within some range/one larger than the other, etc
• add link to example/tutorial on black use in CI
• collect/add more reference to recommended resources for further reading, etc