docs: customer tiers tutorial (#14122)

* docs: customer tiers tutorial

* fix lint error

www/apps/resources/generated/generated-how-to-tutorials-sidebar.mjs

@@ -460,6 +460,15 @@ const generatedgeneratedHowToTutorialsSidebarSidebar = {
           "description": "Learn how to use prices from external systems for products.",
           "children": []
         },
+        {
+          "loaded": true,
+          "isPathHref": true,
+          "type": "link",
+          "title": "Customer Tiers",
+          "path": "/how-to-tutorials/tutorials/customer-tiers",
+          "description": "Learn how to implement customer tiers in your Medusa store.",
+          "children": []
+        },
         {
           "loaded": true,
           "isPathHref": true,