Update how_to_download_models_zh_cn.md

use git lfs clone to download model from ModelScope

docs/how_to_download_models_zh_cn.md

@@ -34,7 +34,7 @@ model_dir = snapshot_download('wanderkid/PDF-Extract-Kit')
 也可以使用git clone从 ModelScope 下载模型:
 
 ```bash
-git clone https://www.modelscope.cn/wanderkid/PDF-Extract-Kit.git
+git lfs clone https://www.modelscope.cn/wanderkid/PDF-Extract-Kit.git
 ```