Update CHANGELOG for auto-release v0.23.1

Author: GitHub Bot

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## [Unreleased]
 
+## [v0.23.1] - 2022-05-03
+
 -   [DOC] Updated `fill.py` and `update_where.py` documentation with working examples.
 -   [ENH] Deprecate `num_bins` from `bin_numeric` in favour of `bins`, and allow generic `**kwargs` to be passed into `pd.cut`. Issue #969. @thatlittleboy
 -   [ENH] Fix `concatenate_columns` not working on category inputs @zbarry
@@ -286,7 +288,9 @@ We thank all contributors
 who have helped make `pyjanitor`
 the package that it is today.
 
-[Unreleased]: https://github.com/pyjanitor-devs/pyjanitor/compare/v0.22.0...HEAD
+[Unreleased]: https://github.com/pyjanitor-devs/pyjanitor/compare/v0.23.1...HEAD
+
+[v0.23.1]: https://github.com/pyjanitor-devs/pyjanitor/compare/v0.22.0...v0.23.1
 
 [v0.22.0]: https://github.com/pyjanitor-devs/pyjanitor/compare/v0.21.2...v0.22.0