DOC: fixing override of built-in functions in docs
- [x] closes #47606  
- [x] [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).
- [x] Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
- [x] Added an entry in the latest `doc/source/user_guide/groupby.rst` file if fixing a bug or adding a new feature.

Thanks for the pull request, but agreed with @phofl's reasoning and `columns` naming should remain here (we used this naming convention in the code base).

Since the original issue was addressed by https://github.com/pandas-dev/pandas/pull/47631 closing as a duplicate, but happy to have a contribution to any of the other documentation issues  