Minor: Fix array coordinates example

[btbest]

The example claims to show an array of shape (2, 3), but it actually shows an array of shape (3, 2) and also lists one out-of-range coordinate (3, 1)...

>>> numpy.ones((2, 3))
array([[1., 1., 1.],
       [1., 1., 1.]])

[github-actions]

Automated Review URLs

• Readthedocs