fixed toc typo

Author: bandersmsft

articles/cost-management-billing/toc.yml

@@ -54,7 +54,7 @@
         href: costs/group-filter.md
     - name: Plan to manage costs
       href: understand/plan-manage-costs.md
-    - name: Identify cosst anomalies and unexpected changes
+    - name: Identify cost anomalies and unexpected changes
       href: understand/analyze-unexpected-charges.md
     - name: Manage costs with automation
       href: costs/manage-automation.md