Update README.md to include comprehensive documentation for ThinkPHP 8, featuring installation instructions, new features, sponsorship details, and links to resources.

app/AppService.php

@@ -0,0 +1,22 @@
+<?php
+declare (strict_types = 1);
+
+namespace app;
+
+use think\Service;
+
+/**
+ * 应用服务类
+ */
+class AppService extends Service
+{
+    public function register()
+    {
+        // 服务注册
+    }
+
+    public function boot()
+    {
+        // 服务启动
+    }
+}