Switch nix formatter and lsp

Change formatter alejandra -> nixfmt (new official formatter)
Change LSP nil -> nixd for more features

home/emacs/default.nix

@@ -3,8 +3,9 @@
   pkgs,
   fonts,
   ...
-}: {
-  imports = [../shell/default.nix];
+}:
+{
+  imports = [ ../shell/default.nix ];
   services.emacs = {
     enable = true;
     package = config.programs.emacs.finalPackage;
@@ -18,7 +19,8 @@
     # git clone https://git.xenia.me.uk/pixelifytica/emacs.git ~/.emacs.d
     enable = true;
     package = pkgs.emacs29-pgtk;
-    extraConfig = let
+    extraConfig =
+      let
         fixed-font-family = "${fonts.monospace.name}";
         variable-font-family = "${fonts.sansSerif.name}";
         font-height = builtins.toString (builtins.floor (builtins.mul fonts.sizes.applications 10));
@@ -45,12 +47,17 @@
           '';
         };
         custom-theme-hash = builtins.hashFile "sha256" "${custom-theme}/${custom-theme-name}-theme.el";
-    in ''
+      in
+      ''
         (add-to-list 'custom-theme-load-path "${custom-theme}")
         (add-to-list 'custom-safe-themes "${custom-theme-hash}")
         (load-theme '${custom-theme-name})
       '';
-    extraPackages = epkgs: with epkgs; [treesit-grammars.with-all-grammars mu4e];
+    extraPackages =
+      epkgs: with epkgs; [
+        treesit-grammars.with-all-grammars
+        mu4e
+      ];
   };
   home.packages = with pkgs; [
     # Emacs requirements
@@ -68,8 +75,18 @@
     mp3info
 
     # Customised LaTeX install
-    (texlive.combine
-      {inherit (pkgs.texlive) scheme-medium dvisvgm dvipng wrapfig amsmath ulem hyperref capt-of;})
+    (texlive.combine {
+      inherit (texlive)
+        scheme-medium
+        dvisvgm
+        dvipng
+        wrapfig
+        amsmath
+        ulem
+        hyperref
+        capt-of
+        ;
+    })
 
     # Development tools
     ## Code screenshots
@@ -86,20 +103,19 @@
     nodePackages.eslint
 
     ## Formatters
-    alejandra
+    nixfmt-rfc-style
     shfmt
     stylua
     nodePackages.prettier
 
     ## Language servers
-    nil # Nix lsp
+    nixd
     lua-language-server
     nodePackages.typescript-language-server
 
     ## Interpreters
-    (python3.withPackages
-      (ps:
-        with ps; [
+    (python3.withPackages (
+      ps: with ps; [
         tkinter
         python-lsp-server
         mypy
@@ -107,9 +123,9 @@
         scipy
         xarray
         matplotlib
-        ]))
-    (luajit.withPackages
-      (ps: [(ps.callPackage ./luarocks/scilua.nix {})]))
+      ]
+    ))
+    (luajit.withPackages (ps: [ (ps.callPackage ./luarocks/scilua.nix { }) ]))
   ];
   xdg.configFile = {
     "ruff/pyproject.toml".source = ./ruff.toml;