Update README.md with sycl description

Author: ZhaoqiongZ

README.md

@@ -5,6 +5,11 @@ An example of writing a C++/CUDA/Sycl extension for PyTorch. See
 This repo demonstrates how to write an example `extension_cpp.ops.mymuladd`
 custom op that has both custom CPU and CUDA/Sycl kernels.
 
+
+> **Note:**
+  `SYCL` serves as the backend programming language for Intel GPUs (device label `xpu`). For configuration details, see:
+  [Getting Started on Intel GPUs](https://docs.pytorch.org/docs/main/notes/get_start_xpu.html).
+
 The examples in this repo work with PyTorch 2.4 or later for C++/CUDA & PyTorch 2.8 or later for Sycl.
 
 To build: