DOC: Clarified pandas_version in to_json
- [X] closes #26637
- [ ] tests added / passed
- [X] passes `black pandas`
- [ ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

Hello @tnwei! 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 2020-10-12 15:07:54 UTC Thanks @arw2019 for the review, edited wording as suggested thanks @tnwei  Thanks for merging @jreback . Hacktoberfest brought me here, would you mind adding the `hacktoberfest-accepted` label to this PR? TQVM! > Thanks for merging @jreback . Hacktoberfest brought me here, would you mind adding the `hacktoberfest-accepted` label to this PR? TQVM!

no problem