Add missing Python function docstrings

[glenn-jocher]

🛠️ PR Summary

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🌟 Summary

Refactoring code for better readability and adding fallbacks to prevent errors.

📊 Key Changes

• Added a blank line in the learning rate function definition to improve readability.
• Renamed the forward function to _forward in the yolo.py file to clarify its purpose.
• Included a fallback method in logger/__init__.py for SummaryWriter to prevent errors if TensorBoard is not installed.

🎯 Purpose & Impact

• 🧹 Readability Improvement: Small tweaks make the code easier for developers to read and maintain.
• 🛠️ Function Clarification: Renaming the function helps in understanding its role in the code, making it more intuitive for developers.
• 🌟 Error Prevention: The fallback for SummaryWriter ensures the system doesn't break if TensorBoard is absent, improving robustness and user experience.