chore: moved zookeeper and website to packages

packages/zookeeper/default.nix

@@ -0,0 +1,25 @@
+{
+  perSystem =
+    { pkgs, ... }:
+    let
+      hp = pkgs.haskellPackages;
+      zookeeper = hp.callCabal2nix "zookeeper" ./. { };
+    in
+    {
+      devShells.zookeeper = hp.shellFor {
+        nativeBuildInputs = builtins.attrValues {
+          inherit (pkgs)
+            nil
+            stylish-haskell
+            ;
+          inherit (hp)
+            cabal-install
+            cabal-gild
+            haskell-language-server
+            ;
+        };
+        packages = _: [ zookeeper ];
+      };
+      packages = { inherit zookeeper; };
+    };
+}