add direnv and set up haskell ls for xmonad work

.envrc

@@ -0,0 +1 @@
+use flake

.gitignore

@@ -1 +1,2 @@
 result
+.direnv/

flake.nix

@@ -30,7 +30,16 @@
     nixos-hardware,
     mac-brcm-fw,
     ...
-  } @ inputs: {
+  } @ inputs: let
+    pkgs = nixpkgs.legacyPackages."x86_64-linux";
+  in {
+    devShells."x86_64-linux".default = pkgs.mkShell {
+      buildInputs = [
+        (pkgs.haskellPackages.ghcWithPackages
+          (pkgs: with pkgs; [xmonad xmonad-contrib]))
+        pkgs.haskell-language-server
+      ];
+    };
     nixosConfigurations = {
       monosodium-glutamate-g = nixpkgs.lib.nixosSystem {
         specialArgs = {

modules/shell/helix.nix

@@ -4,7 +4,6 @@
       sessionVariables.EDITOR = "hx";
       packages = [
         pkgs.nil
-        pkgs.haskell-language-server
         pkgs.nodePackages_latest.vscode-html-languageserver-bin
         pkgs.nodePackages_latest.vscode-json-languageserver-bin
         pkgs.nodePackages_latest.vscode-css-languageserver-bin