REF/TYP: extract function/type args in describe.py
- [ ] xref #36833
- [ ] tests added / passed
- [ ] Ensure all linting tests pass, see [here](https://pandas.pydata.org/pandas-docs/dev/development/contributing.html#code-standards) for how to run them
- [ ] whatsnew entry

Extracted function ``_refine_percentiles`` and typed function arguments in ``pandas/core/describe.py``.