[FEATURE] Gracefully handle mapbox 403 errors in development mode

[ethancrawford]

Is your feature request related to a problem? Please describe. Presently, when attempting to load the map example pages in development mode, the maps appear as blank grey rectangles.

Describe the solution you'd like It would be nice if there was a way to indicate in development mode that mapbox maps will not load as they do in production, due to API permissions, by adding messages to the page.

Describe alternatives you've considered

Happy for other's thoughts on this.

• We could overlay a message on top of each map container?
• Or, we could add a message to the page's intro description?
• We could add static screenshots in place of the live maps?

Google Maps handles it like this: