fixup! ENH: Add blocks to Styler template

Author: TomAugspurger

doc/source/whatsnew/v0.20.0.txt

@@ -359,6 +359,8 @@ Other Enhancements
 - ``pd.read_html()`` will parse multiple header rows, creating a multiindex header. (:issue:`13434`).
 - HTML table output skips ``colspan`` or ``rowspan`` attribute if equal to 1. (:issue:`15403`)
 - ``pd.Styler`` template now has blocks for easier extension (:issue:`15649`)
+- ``pd.Styler.render`` now accepts ``**kwargs`` to allow user-defined variables in the template (:issue:`15649`)
+
 
 - ``pd.TimedeltaIndex`` now has a custom datetick formatter specifically designed for nanosecond level precision (:issue:`8711`)
 - ``pd.types.concat.union_categoricals`` gained the ``ignore_ordered`` argument to allow ignoring the ordered attribute of unioned categoricals (:issue:`13410`). See the :ref:`categorical union docs <categorical.union>` for more information.