docs(README_zh-CN_v2): add note on GPU acceleration for CUDA supported devices

Add a note in the README_zh-CN_v2.md to clarify the availability of GPU
acceleration for devices supporting CUDA, directing users to specific
tutorials based on their operating system.

README_zh-CN_v2.md

@@ -206,6 +206,8 @@ cp magic-pdf.template.json ~/magic-pdf.json
 ```
 
 ### 使用GPU
+如果您的设备支持CUDA，且满足主线环境中的显卡要求，则可以使用GPU加速，请根据自己的系统选择适合的教程：
+
 - [Ubuntu22.04LTS + GPU](docs/README_Ubuntu_CUDA_Acceleration_zh_CN.md)
 - [Windows10/11 + GPU](docs/README_Windows_CUDA_Acceleration_zh_CN.md)