Please provide a ModelScope mirror for Chinese users who cannot easily download large models from Hugging Face

Hi,

Thank you for creating DS4 and sharing this great project.

I noticed that the official DeepSeek model is available through both Hugging Face and ModelScope. For example, users can download the official DeepSeek-V4-Flash model from ModelScope with:

```bash
modelscope download --model deepseek-ai/DeepSeek-V4-Flash