move examples to fix warning

doc/examples/text/lib/main.dart

@@ -0,0 +1,59 @@
+import 'dart:ui';
+
+import 'package:flame/anchor.dart';
+import 'package:flame/components/text_box_component.dart';
+import 'package:flame/components/text_component.dart';
+import 'package:flame/flame.dart';
+import 'package:flame/game.dart';
+import 'package:flame/palette.dart';
+import 'package:flame/text_config.dart';
+import 'package:flutter/material.dart';
+
+void main() => runApp(new MyGame().widget);
+
+TextConfig regular = TextConfig(color: BasicPalette.white.color);
+TextConfig tiny = regular.withFontSize(12.0);
+
+class MyTextBox extends TextBoxComponent {
+  MyTextBox(String text) : super(text, config: tiny, boxConfig: TextBoxConfig(timePerChar: 0.05));
+
+  @override
+  void drawBackground(Canvas c) {
+    Rect rect = Rect.fromLTWH(0, 0, width, height);
+    c.drawRect(rect, new Paint()..color = Color(0xFFFF00FF));
+    c.drawRect(
+        rect.deflate(boxConfig.margin),
+        new Paint()
+          ..color = BasicPalette.black.color
+          ..style = PaintingStyle.stroke);
+  }
+}
+
+class MyGame extends BaseGame {
+  MyGame() {
+    _start();
+  }
+
+  _start() async {
+    Size size = await Flame.util.initialDimensions();
+
+    add(TextComponent('Hello, Flame', config: regular)
+      ..anchor = Anchor.topCenter
+      ..x = size.width / 2
+      ..y = 32.0);
+
+    add(TextComponent('center', config: tiny)
+      ..anchor = Anchor.center
+      ..x = size.width / 2
+      ..y = size.height / 2);
+
+    add(TextComponent('bottomRight', config: tiny)
+      ..anchor = Anchor.bottomRight
+      ..x = size.width
+      ..y = size.height);
+
+    add(MyTextBox('Lorem ipsum dolor sit amet, consectetur adipiscing elit. Etiam eget ligula eu lectus lobortis condimentum.')
+      ..anchor = Anchor.bottomLeft
+      ..y = size.height);
+  }
+}