By searching pnpm on search.nixos.org . It seems only option to install pnpm is to use
nodePackages.pnpm. But I want to install
pnpm as standalone (It installs pnpm even before installing node).
By this I can use pnpm as node version manager too.
Documentation to install pnpm as standalone can be found here Installation | pnpm
Basically we have to run
curl -fsSL https://get.pnpm.io/install.sh | sh - .
I am wondering how to install this declaratively in my nixos (it uses flakes)