Rename example to combined_effects to follow convention

doc/examples/effects/combined_effects/lib/main.dart

@@ -0,0 +1,71 @@
+import 'package:flame/effects/combined_effect.dart';
+import 'package:flame/effects/move_effect.dart';
+import 'package:flame/effects/scale_effect.dart';
+import 'package:flame/effects/rotate_effect.dart';
+import 'package:flame/gestures.dart';
+import 'package:flame/position.dart';
+import 'package:flame/flame.dart';
+import 'package:flame/game.dart';
+import 'package:flutter/material.dart';
+
+import 'dart:math';
+
+import './square.dart';
+
+void main() async {
+  WidgetsFlutterBinding.ensureInitialized();
+  await Flame.util.fullScreen();
+  runApp(MyGame().widget);
+}
+
+class MyGame extends BaseGame with TapDetector {
+  Square greenSquare;
+
+  MyGame() {
+    final green = Paint()..color = const Color(0xAA338833);
+    final red = Paint()..color = const Color(0xAA883333);
+    greenSquare = Square(green, 100, 100);
+    final redSquare = Square(red, 100, 100);
+    add(greenSquare);
+    add(redSquare);
+  }
+
+  @override
+  void onTapUp(TapUpDetails details) {
+    final dx = details.localPosition.dx;
+    final dy = details.localPosition.dy;
+    greenSquare.clearEffects();
+
+    final move = MoveEffect(
+      destination: Position(dx, dy),
+      speed: 250.0,
+      curve: Curves.linear,
+      isInfinite: false,
+      isAlternating: false,
+    );
+
+    final scale = ScaleEffect(
+      size: Size(dx, dy),
+      speed: 250.0,
+      curve: Curves.linear,
+      isInfinite: false,
+      isAlternating: false,
+    );
+
+    final rotate = RotateEffect(
+      radians: (dx + dy) % pi,
+      speed: 1.5,
+      curve: Curves.decelerate,
+      isInfinite: false,
+      isAlternating: false,
+    );
+
+    final combination = CombinedEffect(
+      effects: [move, rotate, scale],
+      isInfinite: false,
+      isAlternating: true,
+      offset: 0.5,
+    );
+    greenSquare.addEffect(combination);
+  }
+}