add readme

Author: seregazhuk

README.md

@@ -1 +1,47 @@
+# Memcached cache implementation for react/cache
+
 [![Build Status](https://travis-ci.org/seregazhuk/php-react-cache-memcached.svg?branch=master)](https://travis-ci.org/seregazhuk/php-react-cache-memcached)
+
+Implementation of [react/cache interface](https://github.com/reactphp/cache) that uses Memcached as a storage.
+
+**Table of Contents**
+- [Installation](#installation)
+- [Quick Start](#quick-start)
+
+## Installation
+
+Library requires PHP 5.6.0 or above.
+
+The recommended way to install this library is via [Composer](https://getcomposer.org). 
+[New to Composer?](https://getcomposer.org/doc/00-intro.md)
+
+See also the [CHANGELOG](CHANGELOG.md) for details about version upgrades.
+
+```
+composer require seregazhuk/react-cache-memcached
+```
+
+## Quick Start
+
+`React\Cache\CacheInterface` has three simple methods to store, retrieve and remove data: 
+
+use React\EventLoop\Factory;
+use seregazhuk\React\Cache\Memcached\Memcached;
+
+$loop = Factory::create();
+$cache = new Memcached($loop);
+
+// store
+$cache->set('key', 12345);
+
+// retrieve
+$cache->get('key')->then(function($value){
+    // handle data
+});
+
+// ...
+
+// remove
+$cache->remove('key');
+
+$loop->run();