fix typo in whatsnew

Author: nchmura4

doc/source/whatsnew/v0.22.0.txt

@@ -25,7 +25,7 @@ Other Enhancements
 - Better support for :func:`Dataframe.style.to_excel` output with the ``xlsxwriter`` engine. (:issue:`16149`)
 - :func:`pandas.tseries.frequencies.to_offset` now accepts leading '+' signs e.g. '+1h'. (:issue:`18171`)
 - :class:`pandas.io.formats.style.Styler` now has ``index`` parameter and corresponding method ``hide_index()`` to determine whether the index will be rendered in ouptut (:issue:`14194`)
-- :class:`pandas.io.formats.style.Styler` now has ``hidden_cols`` parameter and corresponding method ``hide_columns()`` to determine whether columns will be hidden in output (:issue:`14194`)-
+- :class:`pandas.io.formats.style.Styler` now has ``hidden_cols`` parameter and corresponding method ``hide_columns()`` to determine whether columns will be hidden in output (:issue:`14194`)
 
 .. _whatsnew_0220.api_breaking: