Fix YOLO model download URL in models/README.md

[avrabe]

Problem

The model download URL in models/README.md points to a non-existent file:

https://github.com/ultralytics/assets/releases/download/v0.0.0/yolov8n.onnx

This returns 404. The ultralytics/assets releases only contain .pt (PyTorch) files, not pre-exported ONNX models.

Working Alternative

The YOLOv8n ONNX model is available on HuggingFace:

https://huggingface.co/Kalray/yolov8/resolve/main/yolov8n.onnx

This is a 12.8 MB file that works correctly with the yolo_inference component.

Suggested Fix

Update models/README.md to use the HuggingFace URL:

curl -L -o models/yolov8n.onnx \
  https://huggingface.co/Kalray/yolov8/resolve/main/yolov8n.onnx

Alternatively, export from the PyTorch model:

pip install ultralytics
yolo export model=yolov8n.pt format=onnx