Update readme and add examples.

Author: PATROMO

README.md

@@ -1,9 +1,20 @@
 easybill PHP SDK
 ================
 
+[![Latest Stable Version](https://poser.pugx.org/easybill/php-sdk/v/stable.png)](https://packagist.org/packages/easybill/php-sdk) [![Total Downloads](https://poser.pugx.org/easybill/php-sdk/downloads.png)](https://packagist.org/packages/easybill/php-sdk) [![Latest Unstable Version](https://poser.pugx.org/easybill/php-sdk/v/unstable.png)](https://packagist.org/packages/easybill/php-sdk) [![License](https://poser.pugx.org/easybill/php-sdk/license.png)](https://packagist.org/packages/easybill/php-sdk)
+
 Switch SDK to [REST API](https://www.easybill.de/api/) **under development!** 
 
-### Usage
+## Installation
+The recommended way of installing this library is using [Composer](http://getcomposer.org/). 
+
+Add this repository to your composer information using the following command
+
+```bash
+composer require easybill/php-sdk
+```
+
+## Usage
 
 ```php
 use easybill\SDK\Client;
@@ -16,29 +27,18 @@ $result = $client->request('GET', 'documents');
 print_r($result);
 ```
 
-Output:
+## More examples
 
-```
-Array
-(
-    [page] => 1
-    [pages] => 1
-    [limit] => 100
-    [total] => 1
-    [items] => Array
-        (
-            [0] => Array
-                (
-                    ... truncated!
-                )
-        )        
-)
-```
+Check the **examples** folder.
+
+## Documentation
+
+Please see https://www.easybill.de/api for up-to-date documentation.
 
-### Contributing
+## Contributing
 
 Please feel free to send bug reports and pull requests.
 
-### License
+## License
 
 Published as open source under the terms of [MIT License](http://opensource.org/licenses/MIT).

examples/customers_01_load-list.php

@@ -0,0 +1,12 @@
+<?php
+
+require_once '../vendor/autoload.php';
+
+use easybill\SDK\Client;
+use easybill\SDK\Endpoint;
+
+$client = new Client(new Endpoint('... your API key ...'));
+
+$result = $client->request('GET', 'customers');
+
+print_r($result);

examples/customers_02_create.php

@@ -0,0 +1,19 @@
+<?php
+
+require_once '../vendor/autoload.php';
+
+use easybill\SDK\Client;
+use easybill\SDK\Endpoint;
+
+$client = new Client(new Endpoint('... your API key ...'));
+
+$result = $client->request('POST', 'customers', [
+    'first_name'   => 'Foo',
+    'last_name'    => 'Bar',
+    'company_name' => 'FooBar GmbH',
+    'emails'       => [
+        'foo.bar@foobar.com',
+    ],
+]);
+
+print_r($result);

examples/customers_03_update.php

@@ -0,0 +1,18 @@
+<?php
+
+require_once '../vendor/autoload.php';
+
+use easybill\SDK\Client;
+use easybill\SDK\Endpoint;
+
+$client = new Client(new Endpoint('... your API key ...'));
+
+$customer_id = '... your customer id ...';
+
+$result = $client->request('PUT', 'customers/' . $customer_id, [
+    'first_name'   => 'Foo2',
+    'last_name'    => 'Bar2',
+    'company_name' => 'FooBar GmbH2',
+]);
+
+print_r($result);

examples/customers_04_delete.php

@@ -0,0 +1,12 @@
+<?php
+
+require_once '../vendor/autoload.php';
+
+use easybill\SDK\Client;
+use easybill\SDK\Endpoint;
+
+$client = new Client(new Endpoint('... your API key ...'));
+
+$customer_id = '... your customer id ...';
+
+$client->request('DELETE', 'customers/' . $customer_id);

examples/documents_01_load-list.php

@@ -0,0 +1,12 @@
+<?php
+
+require_once '../vendor/autoload.php';
+
+use easybill\SDK\Client;
+use easybill\SDK\Endpoint;
+
+$client = new Client(new Endpoint('... your API key ...'));
+
+$result = $client->request('GET', 'documents');
+
+print_r($result);

examples/documents_02_filter-by-number.php

@@ -0,0 +1,15 @@
+<?php
+
+require_once '../vendor/autoload.php';
+
+use easybill\SDK\Client;
+use easybill\SDK\Endpoint;
+
+$client = new Client(new Endpoint('... your API key ...'));
+
+$result = $client->request('GET', 'documents?' . http_build_query([
+        'number' => '2000003338',
+    ])
+);
+
+print_r($result);

examples/documents_03_load-page-2.php

@@ -0,0 +1,16 @@
+<?php
+
+require_once '../vendor/autoload.php';
+
+use easybill\SDK\Client;
+use easybill\SDK\Endpoint;
+
+$client = new Client(new Endpoint('... your API key ...'));
+
+$result = $client->request('GET', 'documents?' . http_build_query([
+        'page'  => '2',
+        'limit' => 10,
+    ])
+);
+
+print_r($result);