Support for nix develop

[johnrichardrinehart]

First, thanks for writing this!

Issue description

I use flakes for development, mostly. nix develop is the new version of nix-shell. Can you support using zsh when nix develop is ran?

Steps to reproduce

Run nix develop with a version of nix that supports flakes.

[chisui]

Similarly to #17 the new nix cli works completely differently to the old one. Supporting it would be the same as writing a new plugin. Additionally the way it handles interactive shells isn't finalized. For now I will only support nix-shell.

[johnrichardrinehart]

Fair enough. Let's say that some ambitious, intrepid nixer wanted to spin up a version of this that would work with nix develop. What projects could they consult and where in the manual/Wiki might they find information that would help them get started?

[chisui]

To be honest, I just look at the c++ code and pester the people on the #nixos IRC. And a bunch of trial and error.

[johnrichardrinehart]

Okay, it sounds like you and I have similar levels of knowledge. Deal. I'll try to find some time to work on this.

Thanks for zsh-nix-shell, @chisui . It's really helpful.