implemented using_theme example

using_theme/lib/main.dart

@@ -0,0 +1,17 @@
+import 'package:flutter/material.dart';
+
+void main() {
+  runApp(new MaterialApp(
+    home: new Scaffold(
+      appBar: new AppBar(
+        title: new Text("Using Theme"),
+      ),
+      body: new Container(
+          child: new Center(
+            child: new Text("Hello World!", style: new TextStyle(color: Colors.white),),
+          ),
+          decoration: new BoxDecoration(color: Colors.purple)),
+    ),
+    theme: new ThemeData(primarySwatch: Colors.deepPurple),
+  ));
+}