Fix multiprocessing for batch creation

[Sukh-P]

Pull Request

Description

• Adding in a fix to the repo (that @dfulu had found and been using locally) that helps use multiprocessing/multiple workers when creating training batches

• Also changing one pip command in the readme

How Has This Been Tested?

This has been tested locally by @dfulu and myself, when specifying num_workers > 1 in the streamed batches config it stops the script from hanging for long periods.

Checklist:

• [X] My code follows OCF's coding style guidelines
• [X] I have performed a self-review of my own code
• [X] I have made corresponding changes to the documentation
• [ ] I have added tests that prove my fix is effective or that my feature works
• [X] I have checked my code and corrected any misspellings

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 57.14%. Comparing base (26ddadf) to head (ef3752e). Report is 40 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #152 +/- ## ======================================= Coverage 57.14% 57.14% ======================================= Files 28 28 Lines 1806 1806 ======================================= Hits 1032 1032 Misses 774 774 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.