make proper dev-shell including vim

flake.nix

@@ -27,7 +27,8 @@
         devShell = haskellPackages.shellFor {
           packages = p: [ defaultPackage ];
           withHoogle = true;
-          buildInputs = with haskellPackages; [
+          buildInputs = with haskellPackages; with pkgs; [
+            vim
             haskell-language-server
             ghcid
             cabal-install

shell.nix

@@ -5,4 +5,13 @@ let
     pkgs.haskellPackages.callCabal2nix "chaoszone" (gitignore ./.) {};
   gitignore = dir: pkgs.nix-gitignore.gitignoreSource [] dir;
 in
-  chaoszone_cz.env
+  pkgs.haskellPackages.shellFor {
+    packages = p: [ chaoszone_cz ];
+    withHoogle = true;
+    buildInputs = with pkgs.haskellPackages; with pkgs; [
+      haskell-language-server
+      ghcid
+      cabal-install
+      vim
+    ];
+  }