Example functions right before "Challenge - Experimenting with keyword arguments" is badly named

[pansapiens]

Right before "Challenge - Experimenting with keyword arguments" challenge, there is a redefined csvs_to_year function which doesn't actually do what the previous versions did (write files). Seems confusing, should be something like min_max_year ?

The whole keyword arg section feels laboured and repetitive, this could probably be slimmed down.