ultralytics 8.2.2 replace COCO128 with COCO8 (#10167)

Signed-off-by: Glenn Jocher <glenn.jocher@ultralytics.com>

README.md

@@ -88,7 +88,7 @@ model = YOLO("yolov8n.yaml")  # build a new model from scratch
 model = YOLO("yolov8n.pt")  # load a pretrained model (recommended for training)
 
 # Use the model
-model.train(data="coco128.yaml", epochs=3)  # train the model
+model.train(data="coco8.yaml", epochs=3)  # train the model
 metrics = model.val()  # evaluate model performance on the validation set
 results = model("https://ultralytics.com/images/bus.jpg")  # predict on an image
 path = model.export(format="onnx")  # export the model to ONNX format