texlive: touchup documentation (#77718)
texlive: touchup documentation (#77718)

The `bash` pragma gives syntax highlighting on the file, and removing the
prompts allows a user to just copy-paste the entire block into the terminal to
run the update.
NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs