update toc

Author: mumian

articles/azure-resource-manager/bicep/toc.yml

@@ -603,7 +603,7 @@
     displayName: build,decompile,install,list-versions,list versions,upgrade,version,module,registry
   - name: Azure PowerShell
     href: /powershell/module/az.resources/
-  - name: Bicep warnings and errors 
+  - name: Bicep core diagnostics 
     items:
     - name: All codes
       href: bicep-core-diagnostics.md