update nix flake to build the site

flake.nix

@@ -11,18 +11,38 @@
 
   outputs = { self, nixpkgs, theme }: 
   let
+    themeName = ((builtins.fromTOML (builtins.readFile "${theme}/theme.toml")).name);
     allSystems = [ "x86_64-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin" ];
-
     forAllSystems = nixpkgs.lib.genAttrs allSystems;
-
     nixpkgsFor = forAllSystems (system: import nixpkgs { inherit system; });
-
   in
   {
+    packages = forAllSystems (system: 
+        let
+          pkgs = nixpkgsFor.${system};
+        in  {
+          default = pkgs.stdenv.mkDerivation rec {
+            name = "softinio-${system}";
+            version = "0.1";
+            src = ./.;
+            nativeBuildInputs = with pkgs; [ zola ];
+            configurePhase = ''
+              mkdir -p themes
+              ln -snf "${theme}" "themes/${themeName}"
+            '';
+            buildPhase = ''
+              zola build 
+            '';
+            installPhase = ''
+              mkdir -p $out
+              cp -r public/* $out 
+            '';
+          };
+    });
+
     devShells = forAllSystems (system: 
         let
           pkgs = nixpkgsFor.${system};
-          themeName = ((builtins.fromTOML (builtins.readFile "${theme}/theme.toml")).name);
         in  {
           default = pkgs.mkShell {
             buildInputs = with pkgs; [ zola ];