Built with blockbuilder.org
Add a polygon and circle layer from the same GeoJSON source
Use Mapbox default style Outdoors-v9 style: "mapbox://styles/mapbox/outdoors-v9
Created a geojson called 'national-park' as the source
https://api.tiles.mapbox.com/mapbox-gl-js/v0.32.1/mapbox-gl.js