Add feature identify / highlight on click

[brendan-ward]

I often use the preview maps for inspecting data before consuming in projects.

It would be very helpful if I could click on a feature, and show info for that feature in a sidebar, popup, etc. This way I could inspect certain features, and verify that they have the right attributes present, and right attribute values.

[brendan-ward]

This would probably be sufficient:
https://www.mapbox.com/mapbox-gl-js/example/polygon-popup-on-click/