docs: Deprecate TapDetector in favour of TapCallbacks

Author: luanpotter

packages/flame/lib/src/events/component_mixins/tap_callbacks.dart

@@ -10,6 +10,9 @@ import 'package:meta/meta.dart';
 /// In addition to adding this mixin, the component must also implement the
 /// [containsLocalPoint] method -- the component will only be considered
 /// "tapped" if the point where the tap has occurred is inside the component.
+///
+/// Note that FlameGame _is_ a [Component] and does implement
+/// [containsLocalPoint]; so this can be used at the game level.
 mixin TapCallbacks on Component {
   void onTapDown(TapDownEvent event) {}
   void onLongTapDown(TapDownEvent event) {}

packages/flame/lib/src/gestures/detectors.dart

@@ -2,7 +2,7 @@ import 'package:flame/src/game/game.dart';
 import 'package:flame/src/gestures/events.dart';
 import 'package:flutter/gestures.dart';
 
-// Basic touch detectors
+@Deprecated('Use TapCallbacks instead')
 mixin TapDetector on Game {
   void onTap() {}
   void onTapCancel() {}