added new line which was removed accidentally

Author: ShisuiUzumaki

doc/source/whatsnew/v2.0.0.rst

@@ -578,6 +578,7 @@ Deprecations
 - :meth:`Index.is_floating` has been deprecated. Use :func:`pandas.api.types.is_float_dtype` instead (:issue:`50042`)
 - :meth:`Index.holds_integer` has been deprecated. Use :func:`pandas.api.types.infer_dtype` instead (:issue:`50243`)
 - :meth:`Index.is_categorical` has been deprecated. Use :func:`pandas.api.types.is_categorical_dtype` instead (:issue:`50042`)
+
 .. ---------------------------------------------------------------------------
 .. _whatsnew_200.prior_deprecations: