DOC: Fix code formatting and typos in Series.tz_localize
- [ ] closes #xxxx
- [ ] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

The missing line feed prevented the example from being formatted as code sample.
Thanks @StefRe 