Rewrite vector design prototype notebook using modern uproot and awkward

[matthewfeickert]

Eventually maybe we can re-add it, it's a great resource for how to write a numba extension (well, it was). Fine to take it out for now.

Originally posted by @henryiii in #272 (comment)

The vector_design_prototype.ipynb was removed in PR #272, but it should be rewritten as it is a useful resource.

[Saransh-cpp]

Dropping in some resources here for the future -

• https://github.com/Saransh-cpp/vector/blob/update-vector-design-prototype/docs/usage/vector_design_prototype.ipynb.
• https://iris-hep.slack.com/archives/C01BBQDEB6X/p1664214223987299

[Saransh-cpp]

The notebook was removed in #545 so this can be closed.

Edit: oops, the issue talks about adding it again as a prototype; opening it again.

[jpivarski]

Oh, when I saw that it was blank, I just assumed it hadn't been written yet. In the new documentation, I was considering adding a section at the end for "adding new backends." That's what this can eventually become.