Figure out labeling scheme to coordinate markers with divs

[egfrank]

Any one of these solutions:

https://stackoverflow.com/questions/25683871/assign-id-to-marker-in-leaflet

This shouldn't be super hard but important just to carefully think through

[egfrank]

Also obviously requires learning about event handlers:

https://leafletjs.com/reference-1.5.0.html#event

https://developer.mozilla.org/en-US/docs/Learn/JavaScript/Building_blocks/Events

http://www.howtocreate.co.uk/referencedvariables.html

[egfrank]

I'm doing it in React now so the hard part is now not worry about the DIVs but rather clearly outlining what user stories I want from this app.