Fix: Broken link to mapbox docs (#968)

Author: awulkan

README.md

@@ -58,7 +58,7 @@ var Draw = new MapboxDraw();
 
 // Map#addControl takes an optional second argument to set the position of the control.
 // If no position is specified the control defaults to `top-right`. See the docs 
-// for more details: https://www.mapbox.com/mapbox-gl-js/api/map#addcontrol
+// for more details: https://docs.mapbox.com/mapbox-gl-js/api/#map#addcontrol
 
 map.addControl(Draw, 'top-left');