add 2.17 as the version used in Nixpkgs unstable

flake.nix

@@ -4,10 +4,11 @@
   inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.05";
   inputs.flake-utils.url = "github:numtide/flake-utils";
   inputs.nix_2-13.url = "github:NixOS/nix/2.13-maintenance";
+  inputs.nix_2-17.url = "github:NixOS/nix/2.17-maintenance";
   # FIXME: the tip of the branch fails to build on Hydra, but we need it chached
   inputs.nix_2-18.url = "github:NixOS/nix/f5f4de6a550327b4b1a06123c2e450f1b92c73b6";
 
-  outputs = { self, nixpkgs, flake-utils, nix_2-13, nix_2-18 }:
+  outputs = inputs@{ self, nixpkgs, flake-utils, ... }:
     flake-utils.lib.eachDefaultSystem (system:
       let
         pkgs = import nixpkgs {
@@ -66,12 +67,15 @@
           '';
           installPhase =
             let
+              inherit (inputs) nix_2-13 nix_2-17 nix_2-18;
               nix_2-13-doc = nix_2-13.packages.${system}.nix.doc;
+              nix_2-17-doc = nix_2-17.packages.${system}.nix.doc;
               nix_2-18-doc = nix_2-18.packages.${system}.nix.doc;
             in
             ''
-              mkdir -p $out/manual/nix/{2.13,2.18}
+              mkdir -p $out/manual/nix/{2.13,2.17,2.18}
               cp -R ${nix_2-13-doc}/share/doc/nix/manual/* $out/manual/nix/2.13
+              cp -R ${nix_2-17-doc}/share/doc/nix/manual/* $out/manual/nix/2.17
               cp -R ${nix_2-18-doc}/share/doc/nix/manual/* $out/manual/nix/2.18
               cp -R build/html/* $out/
             '';

source/reference/nix-manual.md

@@ -4,20 +4,25 @@
 ```{toctree}
 :hidden:
 
-Nix latest (master) <https://hydra.nixos.org/job/nix/master/build.x86_64-linux/latest/download>
-Nix 2.18 (Nixpkgs unstable) <https://nix.dev/manual/nix/2.13/>
+Nix development (master) <https://hydra.nixos.org/job/nix/master/build.x86_64-linux/latest/download>
+Nix 2.18 (latest release) <https://nix.dev/manual/nix/2.18/>
+Nix 2.17 (Nixpkgs unstable) <https://nix.dev/manual/nix/2.17/>
 Nix 2.13 (NixOS 23.05) <https://nix.dev/manual/nix/2.18/>
 ```
 
-- [Nix latest](https://hydra.nixos.org/job/nix/master/build.x86_64-linux/latest/download)
+- [Nix development](https://hydra.nixos.org/job/nix/master/build.x86_64-linux/latest/download)
 
   The latest working build from the `master` branch of the [Nix repository](https://github.com/NixOS/nix)
 
-- [Nix 2.18](https://nix.dev/manual/nix/2.13/)
+- [Nix 2.18](https://nix.dev/manual/nix/2.18/)
 
-  The latest Nix version shipped with Nixpkgs unstable
+  The latest Nix release
 
-- [Nix 2.13 ](https://nix.dev/manual/nix/2.18/)
+- [Nix 2.17](https://nix.dev/manual/nix/2.17/)
+
+  The Nix version shipped with Nixpkgs unstable
+
+- [Nix 2.13 ](https://nix.dev/manual/nix/2.13/)
 
   The Nix version shipped with NixOS 23.05