DOC: write a new dosctring for jax.numpy.vectorize (#2944)
DOC: write a new dosctring for jax.numpy.vectorize (#2944)

* DOC: write a new dosctring for jax.numpy.vectorize

This version is customized entirely for JAX.

* review and typo fixes
google/jax,tensorflow/probability,google/jax,tensorflow/probability,google/jax,google/jax