[AzureAD-Passwordless] Add redirect, remove retired file from TOC

Author: iainfoulds

.openpublishing.redirection.json

@@ -47340,6 +47340,11 @@
       "redirect_url": "/azure/active-directory/authentication/tutorial-configure-custom-password-protection",
       "redirect_document_id": true
     },
+    {
+      "source_path": "articles/security/fundamentals/ad-concepts.md",
+      "redirect_url": "/azure/active-directory/authentication/concept-authentication-passwordless",
+      "redirect_document_id": true
+    },
     {
       "source_path": "articles/media-services/previous/media-services-fmp4-live-ingest-overview.md",
       "redirect_url": "/azure/media-services/media-services-fmp4-live-ingest-overview",

articles/security/fundamentals/TOC.yml

@@ -52,8 +52,6 @@
     href: identity-management-best-practices.md
   - name: Security checklist
     href: steps-secure-identity.md
-  - name: Choose passwordless 
-    href: ad-passwordless.md
   - name: Choose Azure AD authentication
     href: choose-ad-authn.md