docs: phone authentication + otp guide (#12544)

* initial

* docs: phone authentication guide

* small fix

* Twilio SMS -> Twilio

* vale fix

* fix

* fix to auth sidebar

* fixes

* generate

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

@@ -454,6 +454,15 @@ const generatedgeneratedHowToTutorialsSidebarSidebar = {
           "description": "Learn how to migrate data from Magento to Medusa.",
           "children": []
         },
+        {
+          "loaded": true,
+          "isPathHref": true,
+          "type": "link",
+          "title": "Phone Authentication",
+          "path": "/how-to-tutorials/tutorials/phone-auth",
+          "description": "Learn how to allow users to authenticate using their phone numbers.",
+          "children": []
+        },
         {
           "loaded": true,
           "isPathHref": true,