Nix, but with a different frontend (nixcon2023)

This talk hints at how defining Nix packages (and development shells in particular) with another language than Nix influences the way we think about them, and discuss whether there are lessons to be learned from here for Nixpkgs or Nix itself. [Organist](https://github.com/nickel-lang/organist) is a Nickel library and tool aimed at serving as the entry point for all the development tools, and featuring in particular a [Nickel](https://github.com/tweag/nickel) frontend for Nix as an experiment in changing the surface language. Changing the frontend used was also an occasion of changing the way we declare, compose and override packages, with a framework based on merging records (_a la_ module-system) rather than stacked wrapping functions and explicit fixpoints. about this event: https://talks.nixcon.org/nixcon-2023/talk/7LPHTK/