TST: Fix doctests in ``style.py``
The following commits fix the doctests of the ``style.py``, add some redirects to the User Guide, and some expected results.

- [x] closes #42759
- [x] tests added / passed
- [x] Ensure all linting tests pass, see [here](https://pandas.pydata.org/pandas-docs/dev/development/contributing.html#code-standards) for how to run them
