move nixfmt instructions to FAQ (#1131)

all the interesting infromation is upstream, and there's no point in
maintaining a permanently-outdated copy here.

Author: fricklerhandwerk

_redirects

@@ -40,4 +40,4 @@
 /manual/nix/unstable/* https://hydra.nixos.org/job/nix/master/manual/latest/download/1/manual/:splat 200
 /manual/nix/development/* https://hydra.nixos.org/job/nix/master/manual/latest/download/1/manual/:splat 200
 /tutorials/nixos/continuous-integration-github-actions /guides/recipes/continuous-integration-github-actions 301
-
+/guides/recipes/autoformatting /guides/faq#how-to-format-nix-language-code-automatically 301

source/guides/faq.md

@@ -2,6 +2,13 @@
 
 ## Nix
 
+### How to format Nix language code automatically?
+
+[`nixfmt`](https://github.com/NixOS/nixfmt) is the official formatter for {term}`Nix language` code.
+Please refer to its source repository for installation instructions.
+
+`nixfmt` is [used to format all code](https://github.com/NixOS/nixpkgs/blob/master/ci/default.nix) in {term}`Nixpkgs`.
+
 ### How to convert between paths and strings in the Nix language?
 
 See the Nix reference manual on [string interpolation](https://nix.dev/manual/nix/2.19/language/string-interpolation) and [operators on paths and strings](https://nix.dev/manual/nix/2.19/language/operators#string-concatenation)

source/guides/recipes/autoformatting.md

@@ -11,5 +11,4 @@ Managing remote sources <./dependency-management.md>
 Python development environment <./python-environment.md>
 post-build-hook.md
 continuous-integration-github-actions.md
-autoformatting.md
 ```