Implemented argparse for general_JSON2YOLO and update readem with an "How to use" section

[GiorgioSgl]

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

📊 Key Changes

• Implemented argparse in general_json2yolo.py to handle command-line arguments.
• Updated the README.md with a new "How to use" section.
• Added argparse to the requirements.txt file.

🎯 Purpose & Impact

• The introduction of argparse allows users to specify parameters like json_dir and source directly from the command line. This increases flexibility and usability for different datasets.
• The update to the README.md provides clear instructions on how to use the tool, improving accessibility for new users.
• Including argparse in requirements ensures users will have the necessary packages installed.

🌟 Summary

🛠️ The PR enhances the JSON2YOLO tool by adding command-line functionality and user guidance in the documentation.

[hlydecker]

Was gonna submit a pr to do the same thing; CLI arguments make this so much more usable. Would be great for using this in pipelines involving COCO annotation files!

[glenn-jocher]

That's great to hear! Adding CLI arguments does indeed improve usability, especially for integration into annotation pipelines. Your contribution would be much appreciated. Thank you for feedback!