modified readme

README.md

@@ -7,14 +7,32 @@
 ## Install
 Install package via composer
 
-    composer require endpay/endpay-sdk
+```cli
+composer require endpay/endpay-sdk
+```
 
 ## Use
-TODO...
 
-    use Endpay\Endpay;
+### Instance and set configurations
+```php
+use Endpay\Endpay;
 
-    $endpay = new Endpay();
+$endpay = new Endpay();
 
-    $endpay->setCommerceId('commerceId');
-    $endpay->setApiKey('apiKey');
+$endpay->setCommerceId('commerceId');
+$endpay->setApiKey('apiKey');
+```
+
+### Create a payment
+```php
+$payment = $endpay->payments()->create([
+    'subject' => 'Prueba desde SDK PHP',
+    'amount' => 1
+]);
+```
+
+
+### Read a payment
+```php
+$paymentData = $endpay->payments()->read($payment['id']);
+```