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/rhi/d3d12/root-signature/create-desc.md

@@ -0,0 +1,48 @@
+# D3D12RootSignature::CreateDesc
+
+## 函数签名
+
+```cpp
+static D3D12_ROOT_SIGNATURE_DESC CreateDesc(
+    D3D12_ROOT_PARAMETER* parameters,
+    uint32_t parameterCount,
+    D3D12_STATIC_SAMPLER_DESC* samplers = nullptr,
+    uint32_t samplerCount = 0,
+    D3D12_ROOT_SIGNATURE_FLAGS flags = D3D12_ROOT_SIGNATURE_FLAG_ALLOW_INPUT_ASSEMBLER_INPUT_LAYOUT)
+```
+
+## 中文描述
+
+创建根签名描述符。
+
+## 参数
+
+| 参数 | 类型 | 描述 |
+|------|------|------|
+| `parameters` | `D3D12_ROOT_PARAMETER*` | 根参数数组 |
+| `parameterCount` | `uint32_t` | 根参数数量 |
+| `samplers` | `D3D12_STATIC_SAMPLER_DESC*` | 静态采样器数组（可选） |
+| `samplerCount` | `uint32_t` | 静态采样器数量 |
+| `flags` | `D3D12_ROOT_SIGNATURE_FLAGS` | 根签名标志 |
+
+## 返回值
+
+`D3D12_ROOT_SIGNATURE_DESC` - 根签名描述符
+
+## 复杂度
+
+O(1)
+
+## 示例
+
+```cpp
+D3D12_ROOT_SIGNATURE_DESC desc = D3D12RootSignature::CreateDesc(
+    parameters.data(),
+    parameters.size(),
+    samplers.data(),
+    samplers.size());
+```
+
+## 相关文档
+
+- [D3D12RootSignature](root-signature.md) - 类总览