make series axis parameter docs consistent
- [x] closes #47100
- [x] closes #45969 
- [x] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).

Hello @jackgoldsmith4! Thanks for updating this PR. We checked the lines you've touched for [PEP 8](https://www.python.org/dev/peps/pep-0008) issues, and found:



















There are currently no PEP 8 issues detected in this Pull Request. Cheers! :beers: 

##### Comment last updated at 2022-05-27 13:12:39 UTC The one check that's failing seems to be unrelated: https://github.com/codecov/codecov-action/issues/745 Thanks @jackgoldsmith4 