Port local geocoder option from mapbox gl geocoder#219

morgant wants to merge 4 commits intomapbox:mainmapbox/mapbox-gl-directions:mainfrom

DiscoveryMap:port-localGeocoder-option-from-mapbox-gl-geocoderDiscoveryMap/mapbox-gl-directions:port-localGeocoder-option-from-mapbox-gl-geocoderCopy head branch name to clipboard