fix: improve doc link navigation and tree display

- Fix link resolution with proper relative/absolute path handling
- Improve link styling with underline decoration
- Hide leaf nodes from tree, only show directories
- Fix log file path for packaged app

docs/api/resources/resourcemanager/loadgroup.md

@@ -0,0 +1,35 @@
+# ResourceManager::LoadGroup
+
+```cpp
+template<typename T>
+void LoadGroup(const Containers::Array<Containers::String>& paths,
+               std::function<void(ResourceHandle<T>)> callback)
+```
+
+批量异步加载同类资源。为路径数组中的每个路径提交一个异步加载请求，所有加载完成时通过回调通知。
+
+**参数：**
+- `paths` - 资源路径数组
+- `callback` - 每个资源加载完成时的回调
+
+**返回：** 无
+
+**复杂度：** O(k)，k 为路径数量（每个加载为 O(n)）
+
+**示例：**
+
+```cpp
+Containers::Array<Containers::String> texPaths = {
+    "textures/a.png", "textures/b.png", "textures/c.png"
+};
+ResourceManager::Get().LoadGroup<Texture>(texPaths,
+    [](ResourceHandle<Texture> tex) {
+        if (tex.IsValid()) {
+            printf("Loaded: %s\n", tex->GetPath().CStr());
+        }
+    });
+```
+
+## 相关文档
+
+- [ResourceManager 总览](resourcemanager.md) - 返回类总览