What would you like to share?

Hey! I was going through sorts/tim_sort.py and noticed that while
tim_sort() has a proper docstring, the helper functions don't:

• binary_search()
• insertion_sort()
• merge()
• main()

Since this repo is meant for learning, I think adding docstrings
to these functions would make the file more consistent and easier
to understand, especially for beginners.

I'd like to fix this myself and will submit a PR once this is up!

Additional information

No response