Docs: New example of how to verify a webhook when framework does not …

…support PSR7 (#53)

.github/CODEOWNERS

@@ -1 +1 @@
-* @PaddleHQ/dx
+* @PaddleHQ/developer-experience

examples/webhook_verification_PSR7.php

@@ -0,0 +1,26 @@
+<?php
+
+declare(strict_types=1);
+
+require 'vendor/autoload.php';
+
+/*
+ * Verify a webhook request using PSR-7 when using a framework that does not support PSR-7.
+ * Only requirement is to install guzzlehttp/psr7 package `composer require guzzlehttp/psr7`
+ * @see https://developer.paddle.com/webhooks/signature-verification#verify-sdks?utm_source=dx&utm_medium=paddle-php-sdk
+ */
+
+use GuzzleHttp\Psr7\ServerRequest;
+use Paddle\SDK\Notifications\Secret;
+use Paddle\SDK\Notifications\Verifier;
+
+// Create a PSR-7 compliant request object using the global variables, You don't need this line if you are using a framework that supports PSR-7
+$request = ServerRequest::fromGlobals();
+
+$isVerified = (new Verifier())->verify($request, new Secret('WEBHOOK_SECRET_KEY'));
+
+if ($isVerified) {
+    echo "Webhook is verified\n";
+} else {
+    echo "Webhook is not verified\n";
+}