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-integrations-sidebar.mjs

@@ -153,6 +153,14 @@ const generatedgeneratedIntegrationsSidebarSidebar = {
           "path": "/infrastructure-modules/notification/sendgrid",
           "title": "SendGrid",
           "children": []
+        },
+        {
+          "loaded": true,
+          "isPathHref": true,
+          "type": "ref",
+          "path": "/how-to-tutorials/tutorials/phone-auth#step-3-integrate-twilio-sms",
+          "title": "Twilio SMS",
+          "children": []
         }
       ]
     },