docs(scripting): add baseline api reference and guide

docs/api/XCEngine/Scripting/Mono/MonoScriptRuntime/DestroyScriptInstance.md

@@ -0,0 +1,24 @@
+# MonoScriptRuntime::DestroyScriptInstance
+
+**命名空间**: `XCEngine::Scripting`
+
+**类型**: `method`
+
+**头文件**: `XCEngine/Scripting/Mono/MonoScriptRuntime.h`
+
+## 签名
+
+```cpp
+void DestroyScriptInstance(
+    const ScriptRuntimeContext& context) override;
+```
+
+## 当前实现行为
+
+- 通过 `(gameObjectUUID, scriptComponentUUID)` 找到实例缓存。
+- 若有 `gcHandle`，先释放它。
+- 再从实例缓存表删除该项。
+
+## 相关文档
+
+- [CreateScriptInstance](CreateScriptInstance.md)