Add more engaging examples to the documentation

[jeancochrane]

The example for how to use this package is pretty dry right now. We would do well to give more engaging examples, and show how this package can be incorporated into the workflow of an interesting project. (Examples could even be adapted directly from our work on the Crain's article.)

[jeancochrane]

@hancush I recall you made some maps with this library recently – anything that's shareable?

[hancush]

i pulled stats for the police districts!

[jeancochrane]

Nice! Drop me a link to the code? (Unless it's not ready for public viewing)

[hancush]

here ya go (private repo at time of comment)

[hancush]

Another example: https://github.com/datamade/chicago-community-area-ward-demographics/blob/master/scripts/calculate_demographics.py