TYP: Type annotations in pandas/io/formats/printing.py
- [ ] closes #xxxx
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

Couple of comments, generally looks good.  I'm not sure, but it _may_ be the case that since py2 was dropped some usages of pprint_thing throughout the code base are now unnecessary thanks @MomIsBestFriend 