CLN: minor typos MutliIndex -> MultiIndex (#28223)

Author: simonjayhawkins

doc/source/whatsnew/v0.20.0.rst

@@ -495,7 +495,7 @@ Other enhancements
 - :func:`pandas.util.hash_pandas_object` has gained the ability to hash a ``MultiIndex`` (:issue:`15224`)
 - ``Series/DataFrame.squeeze()`` have gained the ``axis`` parameter. (:issue:`15339`)
 - ``DataFrame.to_excel()`` has a new ``freeze_panes`` parameter to turn on Freeze Panes when exporting to Excel (:issue:`15160`)
-- ``pd.read_html()`` will parse multiple header rows, creating a MutliIndex header. (:issue:`13434`).
+- ``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`)
 - :class:`pandas.io.formats.style.Styler` template now has blocks for easier extension, see the :ref:`example notebook </user_guide/style.ipynb#Subclassing>` (:issue:`15649`)
 - :meth:`Styler.render() <pandas.io.formats.style.Styler.render>` now accepts ``**kwargs`` to allow user-defined variables in the template (:issue:`15649`)

pandas/tests/frame/test_reshape.py

@@ -984,7 +984,7 @@ def test_stack_preserve_categorical_dtype(self, ordered, labels):
         df = DataFrame([[10, 11, 12]], columns=cidx)
         result = df.stack()
 
-        # `MutliIndex.from_product` preserves categorical dtype -
+        # `MultiIndex.from_product` preserves categorical dtype -
         # it's tested elsewhere.
         midx = pd.MultiIndex.from_product([df.index, cidx])
         expected = Series([10, 11, 12], index=midx)