docs: update resources API docs

docs/api/resources/mesh/get-sections.md

@@ -0,0 +1,40 @@
+# Mesh::GetSections
+
+```cpp
+const Containers::Array<MeshSection>& GetSections() const;
+```
+
+获取网格的所有分段信息。
+
+**参数：** 无
+
+**返回：** `const Containers::Array<MeshSection>&` - 分段数组的只读引用
+
+**异常：** 无
+
+**线程安全：** ✅
+
+**复杂度：** O(1)
+
+**示例：**
+
+```cpp
+#include "XCEngine/Resources/Mesh.h"
+
+using namespace XCEngine::Resources;
+
+Mesh mesh;
+mesh.SetVertexData(...);
+mesh.SetIndexData(...);
+mesh.AddSection(...);
+
+const auto& sections = mesh.GetSections();
+for (size_t i = 0; i < sections.Size(); ++i) {
+    const MeshSection& section = sections[i];
+    // 处理每个分段
+}
+```
+
+## 相关文档
+
+- [类总览](mesh.md) - 返回类总览