pinwheel: Add nix-mode and hook it up with eglot

hosts/pinwheel/configuration.nix

@@ -26,6 +26,7 @@
       ./modules/firefox
       ./modules/calibre
       ./modules/go
+      ./modules/nix
     ];
 
   nix.settings.experimental-features = [ "nix-command" "flakes" ];

hosts/pinwheel/modules/emacs/config.org

@@ -398,6 +398,9 @@ https://github.com/justbur/emacs-which-key
    )
 
   (use-package eglot
+    :config
+    ;; Ensure `nil` is in your PATH.
+    (add-to-list 'eglot-server-programs '(nix-mode . ("nil")))
     :hook (
            (eglot-managed-mode . alex/eglot-on-save)
            (go-mode . eglot-ensure)
@@ -413,3 +416,12 @@ https://github.com/justbur/emacs-which-key
     )
   )
 #+END_SRC
+** Nix
+#+BEGIN_SRC emacs-lisp
+  (use-package nix-mode
+    :mode "\\.nix$"
+    :hook (
+          (nix-mode . eglot-ensure)
+    )
+  )
+#+END_SRC

hosts/pinwheel/modules/nix/default.nix

@@ -0,0 +1,6 @@
+{ pkgs, ... }:
+{
+  home-manager.users.alex = {
+    home.packages = [ pkgs.nil ];
+  };
+}