docs: product builder tutorial (#13210)

* initial

* docs: product builder tutorial

www/apps/resources/sidebars/how-to-tutorials.mjs

@@ -176,6 +176,13 @@ While tutorials show you a specific use case, they also help you understand how
         description:
           "Learn how to implement pre-order functionality for products in your Medusa store.",
       },
+      {
+        type: "link",
+        title: "Product Builder",
+        path: "/how-to-tutorials/tutorials/product-builder",
+        description:
+          "Learn how to implement a product builder that allows customers to customize products before adding them to the cart.",
+      },
       {
         type: "link",
         title: "Product Reviews",