Add in deprecation msg for (pandas-dev#28547)

Author: cruzzoe

doc/source/whatsnew/v1.1.0.rst

@@ -816,6 +816,8 @@ Deprecations
 - :meth:`util.testing.assert_almost_equal` now accepts both relative and absolute
   precision through the ``rtol``, and ``atol`` parameters, thus deprecating the
   ``check_less_precise`` parameter. (:issue:`13357`).
+-:func:`read_excel` engine argument "xlrd" will no longer be the default engine and 
+will be replaced by "openpyxl" in a future version (:issue:`28547`).
 
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