fix documentation for auto torch mode

@@ -144,8 +144,6 @@ class ToggleFlashlightButton extends StatelessWidget {
               iconSize: 32.0,
               icon: const Icon(Icons.flash_auto),
               onPressed: () async {
-                // This button only turns off the auto mode.
-                // Perhaps we can switch between on / off / auto?
                 await controller.toggleTorch();
               },
             );

@@ -2,7 +2,7 @@
 enum TorchState {
   /// The flashlight turns on automatically in low light conditions.
   ///
-  /// This is currently only supported on iOS.
+  /// This is currently only supported on iOS and MacOS.
   auto(2),
 
   /// The flashlight is off.

@@ -361,6 +361,9 @@ class MobileScannerController extends ValueNotifier<MobileScannerState> {
   ///
   /// Does nothing if the device has no torch,
   /// or if the camera is not running.
+  ///
+  /// If the current torch state is [TorchState.auto],
+  /// the torch is turned on or off depending on its actual current state.
   Future<void> toggleTorch() async {
     _throwIfNotInitialized();