Launch redesigned homepage and developer docs site

Author: jinwandalaohu66

docs/docs/404.html

@@ -16,6 +16,7 @@
     <a class="brand" href=""><img class="brand-mark" src="assets/brand-mark.svg" alt="" width="30" height="30"><span class="brand-text">PythonIDE Docs</span></a>
     <nav class="top-nav" aria-label="主导航">
       <a class="active" href="">文档</a>
+      <a class="" href="pages/agent-development-index/">Agent</a>
       <a class="" href="pages/widget-api-reference/">API 参考</a>
       <a class="" href="pages/appui-cookbook-index/">示例</a>
     </nav>
@@ -266,6 +267,13 @@
 <a class="nav-link" href="pages/miniapp-native-capabilities/">原生能力入口</a>
 </div>
 </details>
+<details class="nav-collection">
+<summary><a href="collections/agent-development/">Agent 开发</a></summary>
+<div class="nav-group">
+<div class="nav-group-title">开始</div>
+<a class="nav-link" href="pages/agent-development-index/">Agent Skills 安装与说明</a>
+</div>
+</details>
 </nav>
     </aside>
     <main class="content">