Update README.md

Author: smalot

README.md

@@ -12,3 +12,46 @@ PHP Wrapper for Kong API Gateway - Microservices Management Layer, delivering hi
 [![Daily Downloads](https://poser.pugx.org/smalot/kong-api/d/daily)](https://packagist.org/packages/smalot/kong-api)
 
 
+Compatibility
+=============
+
+Currently supported Kong version: `0.11`.
+
+Supported services:
+- Api
+- Certificate
+- Consumer
+- Plugin
+- Sni
+- Target
+- Upstream
+
+Requires at least PHP 5.6.
+
+
+Install
+=======
+
+This library can be installed with composer:
+
+````sh
+composer require smalot/kong-api
+````
+
+Usage
+=====
+
+````php
+$factory = new \Smalot\Kong\ServiceFactory();
+/** @var \Smalot\Kong\Services\Api $service */
+$service = $factory->get('api');
+$response = $service->create(
+  [
+    'name' => $name,
+    'uris' => '/ping',
+    'upstream_url' => 'http://ping/',
+  ]
+);
+$api = $response->json();
+var_dump($api);
+````