Add shells/antibody
This is a zsh plugin manager. Its syntax is similar to antigen, but is
much, much faster. It's written in go (making it necessarily faster than
antigen), but can also dump plugin info to a loadable script so that
antibody doesn't need to run at all when spawning new shells.
Antibody is a shell plugin manager made from the ground up thinking about
performance.
It is faster because it can do things concurrently, while Antigen does it
sequentially. It also has the advantage of using a compiled language (go)
instead of a scripting one.