Replace NPM with Nix

[hkailahi]

heneli.dev/heneli-dot-dev/flake.nix

Line 35 in 13d7b2d

pkgs.nodejs-19_x

Revive dream2nix? Or other Nix-first JS tool? Deno over Nix (does that work with vercel?)? Or settle for something like pnpm over Nix?

This might mean bundling app in a container for Vercel.