[Feature suggestion] einops for array indexing

As suggested on Twitter by @colah: https://twitter.com/ch402/status/1539774943214178304

Is there an "einsum version" of gather()? Somehow gather is the most painful function to use when I need it (at least since I started using einsum).

eg. gather(array, "a b inds[a b] c -> a b c", inds=inds) represents indexing into third dim with inds or somethingsh

There are a few more syntax ideas in the Twitter thread. I'm not entirely sure what this could look like, but I agree that array indexing syntax is one of the hardest parts of NumPy that isn't already served by Einops.