Update docs/source/extending/interval-example.rst
Update docs/source/extending/interval-example.rst

Co-authored-by: Eric Wieser <da64e90baec5d084ce3d8e05f3b022ae6d118ff5@gmail.com>
numba/numba,cpcloud/numba,numba/numba,numba/numba,cpcloud/numba,numba/numba,cpcloud/numba,numba/numba,cpcloud/numba,cpcloud/numba