Add --word_timestamps flag for better syncing

[davejab]

Based on this discussion: openai/whisper#1888

Sync accuracy is greatly improved by setting the --word_timestamps True.

Usage:

auto_subtitle video.mkv --word_timestamps True

Possible fix for #28 and #37

[what-the-diff]

PR Summary

• Introduction of New Command Line Argument
  A new functionality has been added that allows the user to include additional command when running this tool. This additional option --word_timestamps is implemented to provide more detailed results. It specifically caters towards extracting precise timings for individual words appearing within the data stream, enhancing the accuracy of output information.