DOC: fix PR09,PR08 docstring errors in pandas.plotting
fixes the errors along with minor changes to standardize kwds -> **kwargs
closes #28687

verified this fixes PR09,PR08 errors with:

```
./scripts/validate_docstrings.py --errors=PR09,PR08 | grep "pandas.plotting"
```

- [x] closes #xxxx
- [x] tests added / passed