Show more examples with config (#202)

* Show more examples with config

* Promote createWithConfig

clients/guzzle6-adapter.rst

@@ -16,21 +16,32 @@ not yet included in your project), run:
 Usage
 -----
 
-Begin by creating a Guzzle client, passing any configuration parameters you
-like::
+To create a Guzzle6 adapter you should use the `createWithConfig()` function. It will let you to pass Guzzle configuration
+to the client::
 
-    use GuzzleHttp\Client as GuzzleClient;
+    use Http\Adapter\Guzzle6\Client as GuzzleAdapter;
 
     $config = [
-        // Config params
+        'verify' => false,
+        'timeout' => 2,
+        'handler' => //...
+        // ...
     ];
-    $guzzle = new GuzzleClient($config);
+    $adapter = GuzzleAdapter::createWithConfig($config);
 
-Then create the adapter::
+.. note::
 
-    use Http\Adapter\Guzzle6\Client as GuzzleAdapter;
+    If you want even more control over your Guzzle object, you may give a Guzzle client as first argument to the adapter's
+    constructor::
 
-    $adapter = new GuzzleAdapter($guzzle);
+        use GuzzleHttp\Client as GuzzleClient;
+        use Http\Adapter\Guzzle6\Client as GuzzleAdapter;
+
+        $config = ['verify' => false ];
+        // ...
+        $guzzle = new GuzzleClient($config);
+        // ...
+        $adapter = new GuzzleAdapter($guzzle);
 
 And use it to send synchronous requests::
 
@@ -50,6 +61,7 @@ Or send asynchronous ones::
     // Returns a Http\Promise\Promise
     $promise = $adapter->sendAsyncRequest(request);
 
+
 .. include:: includes/further-reading-async.inc
 
 .. _Guzzle 6 HTTP client: http://docs.guzzlephp.org/