Confusion between fetchers implemented by builtins and by nixpkgs.

Observations
A note in the section on Fetchers in the Chapter Nix Language Basics, refers to the Nixpkgs Manual on Fetchers but doesnt provide the information that these are distinct from the fetchers built into Nix by default and also have considerable differences.

Relevant Section:
https://nix.dev/tutorials/nix-language#fetchers

See:
https://discourse.nixos.org/t/builtins-fetchurl-vs-nixpkgs-fetchurl/24133

Problem
This can cause confusion as to, if the manual describes the builtin Fetchers or describes Fetchers implemented by nixpkgs. (Atleast it did to me)

Approaches
Make it clear in the note that nixpkgs implements their own fetchers and also additional fetchers over the builtin fetchers. Also note that Fetcher implementations differ and they cant be just interchanged.

Willing to help?
I could make the change I suppose. I have not made any opensource contribution yet, but I like Nix and this guide and I am open to it.

Priorities

Add 👍 to issues you find important.

Start with the Fetchers section in the Nix Language Basics tutorial and compare its note with the Nixpkgs Manual and the linked Discourse discussion. Update the note so readers can distinguish built-in Nix fetchers from nixpkgs fetchers, understand that implementations differ, and know they cannot be interchanged directly.