modules: system: move 'nix'

modules/system/default.nix

@@ -6,6 +6,7 @@
     ./documentation.nix
     ./language.nix
     ./media.nix
+    ./nix.nix
     ./users.nix
   ];
 }

modules/system/nix.nix

@@ -0,0 +1,19 @@
+# Nix related settings
+{ inputs, pkgs, ... }:
+
+{
+  nix = {
+    package = pkgs.nixFlakes;
+    registry = {
+      # Allow me to use my custom package using `nix run self#pkg`
+      self.flake = inputs.self;
+      # Use pinned nixpkgs when using `nix run pkgs#<whatever>`
+      pkgs.flake = inputs.nixpkgs;
+      # Add NUR to run some packages that are only present there
+      nur.flake = inputs.nur;
+    };
+    extraOptions = ''
+      experimental-features = nix-command flakes
+    '';
+  };
+}