add data_columns to doc string
- [x] closes #13061 
- [ ] tests added / passed
- [x] passes `git diff upstream/master | flake8 --diff`
- [ ] whatsnew entry

How about this for #13061 ?
I don't think pandas has tests for each documented field, correct?
Do you want a whatsnew entry for this? If yes, how does that work? The guidelines don't talk about that.
