DOC: add whatsnew for v2.2.3
Add basic whatsnew file skeleton (like https://github.com/pandas-dev/pandas/pull/57759 for 2.2.2), so we can backport this and start add some content.
/preview Website preview of this PR available at: https://pandas.pydata.org/preview/pandas-dev/pandas/59811/ thanks @jorisvandenbossche 