Update readme

Author: barryvdh

readme.md

@@ -13,7 +13,7 @@ After updating composer, add the ServiceProvider to the providers array in app/c
 
     'Barryvdh\Omnipay\ServiceProvider',
 
-You need to publish the config for this package
+You need to publish the config for this package. A sample configuration is provided. The defaults will be merged with gateway specific configuration.
 
     $ php artisan config:publish barryvdh/laravel-omnipay
 
@@ -24,3 +24,33 @@ To use the Facade (`Omnipay::purchase()` instead of `App::make(`omnipay`)->purch
 When calling the Omnipay facade/instance, it will create the default gateway, based on the configuration.
 You can change the default gateway by calling `Omnipay::setDefaultGateway('My\Gateway')`.
 You can get a different gateway by calling `Omnipay::gateway('My\Cass')`
+
+## Examples
+
+    $params = [
+        'amount' => $order->amount,
+        'issuer' => $issuerId,
+        'description' => $order->description,
+        'returnUrl' => URL::action('PurchaseController@return', [$order->id]),
+    ];
+    $response = Omnipay::purchase($params)->send();
+
+    if ($response->isSuccessful()) {
+        // payment was successful: update database
+        print_r($response);
+    } elseif ($response->isRedirect()) {
+        // redirect to offsite payment gateway
+        return $response->getRedirectResponse();
+    } else {
+        // payment failed: display message to customer
+        echo $response->getMessage();
+    }
+
+Besides the gateway calls, there is also a shortcut for the creditcard:
+
+    $formInputData = array(
+        'firstName' => 'Bobby',
+        'lastName' => 'Tables',
+        'number' => '4111111111111111',
+    );
+    $card = Omnipay::CreditCard($formInputData);