Added GitHub webhook functionality and configuration for API interaction

This commit introduces functionality for GitHub webhook interaction and API calls. The git operations are handled by a custom GitHub client in PHP, details for API endpoints are outlined in a new OpenAPI schema, and the project setup includes PHP FPM and NGINX configuration using Docker. A webhook receiver is also added to process incoming webhook payloads.

src/webhookReceiver.php

@@ -0,0 +1,21 @@
+<?php
+
+require 'GitHubClient.php';
+
+$token = getenv('GITHUB_TOKEN');
+$client = new GitHubClient($token);
+
+// Get the webhook payload
+$payload = file_get_contents('php://input');
+$data = json_decode($payload, true);
+
+if (isset($data['commits'])) {
+    foreach ($data['commits'] as $commit) {
+        // Process each commit
+        echo "Commit message: " . $commit['message'] . "\n";
+    }
+}
+
+// Respond to GitHub
+http_response_code(200);
+echo json_encode(['status' => 'Webhook received']);