I thought the commit template is explains itself and contains links. Is there a specific question, you have? In this case no functionality changes, but other pull request do more invasive changes
so it is good to know on which platforms it was tested for example.

The checklist seem to be geared towards people who know what they're doing locally and need only a couple of pointers to figure out what Nixpkgs maintainers need to consider the changes tested. Me being a drive-by contributor with zero experience in writing my own derivations or anything, plus not much time right now to dive into all this stuff (notice the commit date is a week ago?), it presented an insurmountable challenge. The most specific question I can come up with is: where can I find the more extensive documentation on contributing? Not just a list of things I can do with Nix—i.e. not the Nix manual—but specific steps of how I build and test my changes before submitting a PR.

If you're interested what I ran into specifically, here goes.

I've set nix.useSandbox = true in my /etc/nixos/configuration.nix, ran nixos-rebuild switch, and… then what? I assumed I should try nix-build; I ran nix-build sans.nix in pkgs/data/fonts/paratype-pt, but it gave me an error: "cannot auto-call a function that has an argument without a default value (‘stdenv’)". I skimmed the synopsis in the man page, didn't see a clear way forward, and gave up.

nix-shell -p nox --run 'nox-review wip' said it "must be run in a nix repository". But isn't pkgs/data/fonts/paratype-pt a "nix repository"? Again, I gave up.

The third item is the only one I knew what to do about. Fonts don't contain executables :)

Regarding the fourth item: it seems that the box should be ticked by a person who reviews the PR, but then it's not clear why it's even in the checklist.