add the pre-built version of bitsandbytes library for windows user

README.md

@@ -89,6 +89,12 @@ huggingface-cli login
 
 And **powerful GPUs**!
 
+If you want to enable LoRA(QLoRA) or Freeze quantization on Windows, you will be required to install a pre-built version of `bitsandbytes` library, which supports CUDA 11.1 to 12.1.
+
+```
+pip install https://github.com/jllllll/bitsandbytes-windows-webui/releases/download/wheels/bitsandbytes-0.39.1-py3-none-win_amd64.whl
+```
+
 ## Getting Started
 
 ### Data Preparation (optional)