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/iloader/getdefaultsettings.md

@@ -0,0 +1,25 @@
+# IResourceLoader::GetDefaultSettings
+
+```cpp
+ImportSettings* GetDefaultSettings() const = 0
+```
+
+获取此加载器的默认导入设置。纯虚方法，子类返回其特有的默认设置实例。
+
+**参数：** 无
+
+**返回：** 默认 `ImportSettings` 指针，调用者不持有所有权
+
+**复杂度：** O(1)
+
+**示例：**
+
+```cpp
+ImportSettings* TextureLoader::GetDefaultSettings() const {
+    return new TextureImportSettings();
+}
+```
+
+## 相关文档
+
+- [IResourceLoader 总览](iloader.md) - 返回类总览