Update dataset headers (#4162)

data/VOC.yaml

@@ -1,9 +1,10 @@
-# PASCAL VOC dataset http://host.robots.ox.ac.uk/pascal/VOC/
-# Train command: python train.py --data VOC.yaml
-# Default dataset location is next to YOLOv5:
-#   /parent
-#     /datasets/VOC
-#     /yolov5
+# Copyright Ultralytics https://ultralytics.com, licensed under GNU GPL v3.0
+# PASCAL VOC dataset http://host.robots.ox.ac.uk/pascal/VOC
+# YOLOv5 🚀 example usage: python train.py --data VOC.yaml
+# parent
+# ├── yolov5
+# └── datasets
+#     └── VOC  ← downloads here
 
 
 # Train/val/test sets as 1) dir: path/to/imgs, 2) file: path/to/imgs.txt, or 3) list: [path/to/imgs1, path/to/imgs2, ..]