Update comments header (#4184)

data/coco128.yaml

@@ -1,6 +1,6 @@
-# Copyright Ultralytics https://ultralytics.com, licensed under GNU GPL v3.0
+# YOLOv5 🚀 by Ultralytics https://ultralytics.com, licensed under GNU GPL v3.0
 # COCO128 dataset https://www.kaggle.com/ultralytics/coco128 (first 128 images from COCO train2017)
-# YOLOv5 🚀 example usage: python train.py --data coco128.yaml
+# Example usage: python train.py --data coco128.yaml
 # parent
 # ├── yolov5
 # └── datasets