json.choropleth: Create a geojson choropleth of selected regions.
Description
Drawing a choropleth (colored regions based on data values) with GADMTools is straightforward. You just have to select your shape(s) file(s) with gadm_loadcountries, load your data from a
csv file for example, and call the json.choropleth function with the right arguments. json.choropleth creaate a GEOJSON file (output.json) that can be used with Leaflet library.