Fix README.md

Author: aosoft

README.md

@@ -19,5 +19,5 @@ unity-native-plugin = { version = "0.1.0", features = ["d3d11"] }
 * Use UnityInterface::get_interface, which is equivalent to IUnityInterfaces::GetInterface, to get the interface.
 ```rust
 let intf = unity_native_plugin::UnityInterfaces::get_unity_interfaces()
-    .get_interface::<unity_native_plugin::d3d11::UnityGraphicsD3D11>()
+    .get_interface::<unity_native_plugin::d3d11::UnityGraphicsD3D11>();
 ```