Update HUBDatasetStats() usage examples

[glenn-jocher]

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

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Enhancement of dataset statistics utility within the YOLOv5 framework.

📊 Key Changes

• 📝 Updated docstrings in HUBDatasetStats for better clarity on the class purpose.
• ✨ Introduced new methods get_json() and process_images() within the HUBDatasetStats class.

🎯 Purpose & Impact

• 🎓 The clearer documentation aids in understanding how to use the HUBDatasetStats class.
• 🚀 New methods provide functionality for generating JSON statistics and preparing datasets, making dataset handling more efficient.
• 📈 These enhancements may improve developer experience and streamline dataset management procedures for YOLOv5 users.