docs: added pre-orders guide (#12984)

* docs: added pre-orders guide

* fix lint errors

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

@@ -148,6 +148,13 @@ While tutorials show you a specific use case, they also help you understand how
         description:
           "Learn how to allow users to authenticate using their phone numbers.",
       },
+      {
+        type: "link",
+        title: "Pre-Order Products",
+        path: "/how-to-tutorials/tutorials/preorder",
+        description:
+          "Learn how to implement pre-order functionality for products in your Medusa store.",
+      },
       {
         type: "link",
         title: "Product Reviews",