Update Readme

Author: jeffski

README.md

@@ -1,7 +1,30 @@
 # Shotstack PHP SDK
 
-PHP SDK for Shotstack, the cloud video editing API.
+PHP SDK for [Shotstack](http://shotstack.io), the cloud video editing API.
 
-## Requirements
+Shotstack is a cloud based video editing platform that enables the editing of videos uding code.
 
-PHP >= 5.5
+The platform uses an API and a JSON format for specifying how videos should be edited and what assets and titles should be used.
+
+A server based render farm takes care of rendering the videos allowing multiple videos to be created simultaneously.
+
+For examples of how to use the SDK to create videos using code checkout the PHP demo repo: https://github.com/shotstack/php-demos
+
+## Installation
+
+### Composer
+
+The recomended way to use the SDK is as a compoaser package. Install using the command:
+
+```
+composer require shotstack/shotstack-sdk-php
+```
+
+## Documentation
+
+- [Getting Started Guide](https://shotstack.gitbook.io/docs/guides/getting-started)
+- [API Reference](https://shotstack.restlet.io/)
+- [Examples](https://github.com/shotstack/php-demos)
+- [Shotstack Website](http://shotstack.io)
+
+###