zoomRange property

Implementation

Future<(double, double)> get zoomRange async {
  // return (1.0, 2.0);
  controller = await start();
  final maxZoom = await controller!.getMaxZoomLevel();
  final minZoom = await controller!.getMinZoomLevel();
  zoomM.zoomRange = (minZoom, maxZoom);
  return (minZoom, maxZoom);
}