Clearer Vectorized Indexing example (#4433)

* Clearer Vectorized Indexing example

* Feedback from @alexamici

Author: max-sixty

doc/indexing.rst

@@ -339,7 +339,7 @@ MATLAB, or after using the :py:func:`numpy.ix_` helper:
         coords={"x": [0, 1, 2], "y": ["a", "b", "c", "d"]},
     )
     da
-    da[[0, 1], [1, 1]]
+    da[[0, 2, 2], [1, 3]]
 
 For more flexibility, you can supply :py:meth:`~xarray.DataArray` objects
 as indexers.

doc/whats-new.rst

@@ -99,6 +99,8 @@ Documentation
   By `Sander van Rijn <https://github.com/sjvrijn>`_
 - Update the contributing guide to use merges instead of rebasing and state
   that we squash-merge. (:pull:`4355`) By `Justus Magin <https://github.com/keewis>`_.
+- Updated Vectorized Indexing to a clearer example.
+  By `Maximilian Roos <https://github.com/max-sixty>`_
 
 Internal Changes
 ~~~~~~~~~~~~~~~~