Update author and reviewer in index.yml

Author: Nicholak-MS

articles/cost-management-billing/manage/index.yml

@@ -9,8 +9,8 @@ metadata:
   ms.subservice: billing
   ms.topic: landing-page
   author: Nicholak-MS
-  ms.author: nicholak
-  ms.reviewer: nicholak
+  ms.author: mijeffer
+  ms.reviewer: mijeffer
   ms.date: 12/29/2025
 
 # linkListType: architecture | concept | deploy | download | get-started | how-to-guide | learn | overview | quickstart | reference | tutorial | whats-new