Update README per recommendations from Seth:

sky/sdk/README.md

 Sky
 ===
 
 Sky is an experimental, high-performance UI framework for mobile apps. Sky helps
 you create apps with beautiful user interfaces and high-quality interactive
 design that run smoothly at 120 Hz.
 
 Sky consists of two components:
 
 1. *The Sky engine.* The engine is the core of the system. Written in C++, the
@@ skipping 46 matching lines @@
 Sky apps can access services from the host operating system using Mojo. For
 example, you can access the network using the `network_service.mojom` interface.
 Although you can use these low-level interfaces directly, you might prefer to
 access these services via libraries in the framework. For example, the
 `fetch.dart` library wraps the underlying `network_service.mojom` in an
 ergonomic interface:
 
 ```dart
 import 'package:sky/framework/net/fetch.dart';
 
-void main() {
-  fetch('example.txt').then((Response response) {
-    print(response.bodyAsString());
-  });
+main() async {
+  var response = await fetch('example.txt');
+  print(response.bodyAsString());
 }
 ```
 
 Set up your computer
 --------------------
 
 1. Install the Dart SDK:
   - https://www.dartlang.org/tools/download.html
 
 2. Install the ``adb`` tool from the Android SDK:
@@ skipping 19 matching lines @@
 3. Using a USB cable, plug your phone into your computer. If prompted on your
    device, authorize your computer to access your device.
 
 Running a Sky application
 -------------------------
 
 1. ``packages/sky/lib/sky_tool --install examples/stocks/main.sky``
    The --install flag is only necessary the first time to install SkyDemo.apk.
 
 2.  Use ``adb logcat`` to view any errors or Dart print() output from the app.