Add user_config_dir('Ultralytics')

[glenn-jocher]

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Implementation of user configuration directory for platform-specific settings and font management in YOLOv5.

📊 Key Changes

• Added a new user_config_dir function to create or return a user-specific configuration directory.
• Updated the check_font function to use the new user config directory for downloading missing fonts.

🎯 Purpose & Impact

• 🛠 Enhances platform compatibility: The user configuration path adapts to the operating system, improving functionality across Windows, Linux, and macOS.
• 🖌 Improves font management: Fonts are now managed in the user's configuration directory, making the process cleaner and less intrusive.
• 📈 Potential user impact: Both developers and users benefit from a neater installation with settings and resources stored in a dedicated, user-specific location, which can reduce permission issues and improve the overall user experience.

[joaodiogocosta]

@glenn-jocher this breaks AWS Lambdas because /home/... is not writable. Only /tmp is writable.

Is there a way to set the "user config dir" to another location?