docs: update RHI API docs

docs/api/rhi/d3d12/device/create-sampler.md

@@ -0,0 +1,30 @@
+# D3D12Device::CreateSampler
+
+```cpp
+RHISampler* CreateSampler(const SamplerDesc& desc) override;
+```
+
+创建 D3D12 采样器。
+
+**参数：**
+- `desc` - 采样器描述符，包含过滤模式、地址模式等
+
+**返回：** 新创建的采样器指针，失败返回 `nullptr`
+
+**示例：**
+
+```cpp
+SamplerDesc samplerDesc;
+samplerDesc.filter = (uint32_t)D3D12_FILTER_MIN_MAG_MIP_LINEAR;
+samplerDesc.addressU = (uint32_t)D3D12_TEXTURE_ADDRESS_MODE_WRAP;
+samplerDesc.addressV = (uint32_t)D3D12_TEXTURE_ADDRESS_MODE_WRAP;
+samplerDesc.addressW = (uint32_t)D3D12_TEXTURE_ADDRESS_MODE_WRAP;
+
+RHISampler* sampler = device->CreateSampler(samplerDesc);
+```
+
+## 相关文档
+
+- [D3D12Device 总览](device.md) - 返回类总览
+- [RHIDevice::CreateSampler](../../device/create-sampler.md) - 基类方法
+- [D3D12Sampler](../../sampler/sampler.md) - D3D12 采样器实现