Upload an 0.0.0 release.

As a preliminary check for having arti be a real legit set of rust crates, we should get everything into a position where we can upload to crates.io. To do that, we should make sure that our crates have all the pieces that are ordinarily required or recommended; that our inter-crate dependencies are set right; that we have a real plan for upgrading crates over time, and so on.