💡[Feature]: Add nixos-shell bindings

[tsandrini]

Is your feature request related to a problem? Please describe

Create a simple part that would provide bindings for https://github.com/Mic92/nixos-shell

My idea currently is to have a flakeModule that would add $NAME-vm nixosConfigurations and to provide two examples

1. One of a custom empty host with various nixos-shell arguments
2. One that would use an existing host and show how to convert it to a vm?

Should research and try out more stuff though!

---

Add a 👍 [reaction] to [issues you find important].