DOC: Added Docstrings to announce.py and contributors.py
- [ ] closes #58812 
- [ ] [Tests added and passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#writing-tests) if fixing a bug or adding a new feature
- [ ] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [ ] Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
- [ ] Added an entry in the latest `doc/source/whatsnew/vX.X.X.rst` file if fixing a bug or adding a new feature.

Docstrings were added to `get_authors()` , `get_pull_requests()`, `build_string()`, `build_components()`, and `main()` of **announce.py**. Additionally, docstrings were added to `run()` and `setup()` in **contributors.py**.

Thanks for the PR! As mentioned in the issue there is already another open PR that adds the docstrings, and I think we're gonna stick to it because it was opened first.

Really sorry for taking much of your time! But feel free to work on other issues with the `Docs` label, we have lots of other docstrings that need to be improved! ;)