Fix grammar in sky/sdk/README.md

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 25 matching lines @@
 name: your_app_name
 dependencies:
  sky: any
 ```
 
 Once the pubspec is in place, create a `lib` directory (where your dart code
 will go) and run `pub get` to download all necessary dependencies and create
 the symlinks necessary for 'package:your_app_names/main.dart' includes to work.
 
 Currently the Sky Engine assumes the entry point for your application is a
-`main` function is located inside a `main.sky` file at the root of the package.
+`main` function located inside a `main.sky` file at the root of the package.
 `.sky` is an html-like format:
 ```
 <sky>
 <script>
 import 'package:your_app_name/main.dart'
 
 void main() {
   new HelloWorldApp();
 }
 </script>
@@ skipping 130 matching lines @@
 [Keyboard](https://github.com/domokit/mojo/blob/master/mojo/services/keyboard/public/interfaces/keyboard.mojom)
 service to allow Sky Framework Dart code to interface with the underlying
 platform's Keyboard, but also to expose any additional non-Dart business logic
 to Sky/Dart UI code.
 
 As and example, [SkyApplication](https://github.com/domokit/mojo/blob/master/sky/shell/org/domokit/sky/shell/SkyApplication.java)
 exposes a mojo `network_service` (required by Sky Engine C++ code)
 [SkyDemoApplication](https://github.com/domokit/mojo/blob/master/sky/apk/demo/org/domokit/sky/demo/SkyDemoApplication.java)
 additionally exposes `keyboard_service` and `sensor_service` for use by the Sky
 Framework from Dart.