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/parallax/component_parallax_example.dart

@@ -0,0 +1,34 @@
+import 'package:flame/components.dart';
+import 'package:flame/game.dart';
+import 'package:flame/parallax.dart';
+
+class ComponentParallaxExample extends FlameGame {
+  static const String description = '''
+    Shows how to do initiation and loading of assets from within an extended
+    `ParallaxComponent`,
+  ''';
+
+  @override
+  Future<void> onLoad() async {
+    await super.onLoad();
+    add(MyParallaxComponent());
+  }
+}
+
+class MyParallaxComponent extends ParallaxComponent<ComponentParallaxExample> {
+  @override
+  Future<void> onLoad() async {
+    await super.onLoad();
+    parallax = await gameRef.loadParallax(
+      [
+        ParallaxImageData('parallax/bg.png'),
+        ParallaxImageData('parallax/mountain-far.png'),
+        ParallaxImageData('parallax/mountains.png'),
+        ParallaxImageData('parallax/trees.png'),
+        ParallaxImageData('parallax/foreground-trees.png'),
+      ],
+      baseVelocity: Vector2(20, 0),
+      velocityMultiplierDelta: Vector2(1.8, 1.0),
+    );
+  }
+}