Add map clusters to show count of thefts at single location

[stevepiercy]

Multiple points are stacked on top of each other. It's impossible to visualize the actual number of thefts. When a point is clicked, only one theft is shown in the popup.

This example should fix the issue.
https://docs.mapbox.com/mapbox.js/example/v1.0.0/markercluster-with-mapbox-data/

Docs:
https://docs.mapbox.com/help/tutorials/markers-js/#cluster-markers