Migrate examples back, change to monorepo (#701)

examples/lib/stories/sprites/basic.dart

@@ -0,0 +1,16 @@
+import 'package:flame/components.dart';
+import 'package:flame/game.dart';
+
+class BasicSpriteGame extends BaseGame {
+  @override
+  Future<void> onLoad() async {
+    final sprite = await loadSprite('flame.png');
+    add(
+      SpriteComponent(
+        sprite: sprite,
+        position: Vector2.all(100),
+        size: sprite.srcSize * 2,
+      ),
+    );
+  }
+}