docs: update RHI API docs

docs/api/rhi/pipeline-state/unbind.md

@@ -0,0 +1,32 @@
+# RHIPipelineState::Unbind
+
+```cpp
+virtual void Unbind() = 0;
+```
+
+将管线状态从渲染上下文解绑。此方法用于结束当前管线状态的使用，使其不再是当前活跃的渲染管线。
+
+**参数：** 无
+
+**返回：** 无
+
+**线程安全：** ❌
+
+**复杂度：** O(1)
+
+**示例：**
+
+```cpp
+#include "XCEngine/RHI/RHIPipelineState.h"
+
+class MyRenderer {
+    void EndRendering(RHIPipelineState* pipeline) {
+        pipeline->Unbind();
+    }
+};
+```
+
+## 相关文档
+
+- [RHIPipelineState](pipeline-state.md) - 返回类总览
+- [RHIPipelineState::Bind](bind.md) - 绑定管线状态