Imrpoved docstring for np.tensordot()

I feel that the docstring for `np.tensordot()` may be more explicit so users can find words of "tensor product" and "tensor contraction" directly by doing a search. Any comments are welcome.
This is hard to follow, I would prefer something more succinct here, perhaps:

    Number of axes N to sum over (applies, in order, to the last N axes of `a` and the first N of `b`);

If you think more explanation as to what "in order" means is needed, I would put that in the notes.