Unify examples structure (#1118)

* Animations, CameraAndViewport, CollisionDetection and Components unified

* Added descriptions to effects

* Rename input games

* Unify input stories

* Add info to parallax section

* Added descriptions to the rendering examples

* Add descriptions to the sprites directory

* Fix utils and rendering section

* Add descriptions to the widgets section

* Delete directory that rebase brought back

* Unify game names

* Added some styleguide docs for examples

* Fix analyze issues

* All files should have _example as suffix

* Made the FollowComponentExample a bit easier to understand

* Change priority of ember

examples/lib/stories/animations/animation_group_example.dart

@@ -0,0 +1,74 @@
+import 'dart:ui';
+
+import 'package:flame/components.dart';
+import 'package:flame/game.dart';
+import 'package:flame/input.dart';
+
+enum RobotState {
+  idle,
+  running,
+}
+
+class AnimationGroupExample extends FlameGame with TapDetector {
+  static const description = '''
+    This example shows how to create a component that can be switched between
+    different states to change the animation that is playing.\n\n
+    
+    Usage: Click/tap and hold the screen to change state and then let go to go
+    back to the original animation.
+  ''';
+
+  late SpriteAnimationGroupComponent robot;
+
+  @override
+  Future<void> onLoad() async {
+    await super.onLoad();
+    final running = await loadSpriteAnimation(
+      'animations/robot.png',
+      SpriteAnimationData.sequenced(
+        amount: 8,
+        stepTime: 0.2,
+        textureSize: Vector2(16, 18),
+      ),
+    );
+    final idle = await loadSpriteAnimation(
+      'animations/robot-idle.png',
+      SpriteAnimationData.sequenced(
+        amount: 4,
+        stepTime: 0.4,
+        textureSize: Vector2(16, 18),
+      ),
+    );
+
+    final robotSize = Vector2(64, 72);
+    robot = SpriteAnimationGroupComponent<RobotState>(
+      animations: {
+        RobotState.running: running,
+        RobotState.idle: idle,
+      },
+      current: RobotState.idle,
+      position: size / 2 - robotSize / 2,
+      size: robotSize,
+    );
+
+    add(robot);
+  }
+
+  @override
+  void onTapDown(_) {
+    robot.current = RobotState.running;
+  }
+
+  @override
+  void onTapCancel() {
+    robot.current = RobotState.idle;
+  }
+
+  @override
+  void onTapUp(_) {
+    robot.current = RobotState.idle;
+  }
+
+  @override
+  Color backgroundColor() => const Color(0xFF222222);
+}