Standardize license headers in TOML/YAML files (#13491)

Refactor code for speed and clarity

Co-authored-by: Glenn Jocher <glenn.jocher@ultralytics.com>

data/xView.yaml

@@ -1,4 +1,5 @@
-# Ultralytics YOLOv5 🚀, AGPL-3.0 license
+# Ultralytics 🚀 AGPL-3.0 License - https://ultralytics.com/license
+
 # DIUx xView 2018 Challenge https://challenge.xviewdataset.org by U.S. National Geospatial-Intelligence Agency (NGA)
 # --------  DOWNLOAD DATA MANUALLY and jar xf val_images.zip to 'datasets/xView' before running train command!  --------
 # Example usage: python train.py --data xView.yaml