GitHub is transitioning map rendering services from MapBox to Azure Maps in our Free, Pro, and Team plans. This includes maps embedded in the site file viewer, embedded maps, and maps rendered in markdown. As part of the transition, custom icons and formatting of features in geojson and topojson files will no longer be supported. This change will not impact our Enterprise Cloud instances which will continue to use MapBox for map rendering. Documentation can be found here: https://docs.github.com/en/repositories/working-with-files/using-files/working-with-non-code-files#geometry-types