fixing h2 level

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cc: @batamig

Author: batamig

articles/sentinel/whats-new.md

@@ -209,7 +209,7 @@ For example:
 
 For more information, see [Use Jupyter notebooks to hunt for security threats](notebooks.md).
 
-## Microsoft Sentinel renaming
+### Microsoft Sentinel renaming
 
 Starting in November 2021, Azure Sentinel is being renamed to Microsoft Sentinel, and you'll see upcoming updates in the portal, documentation, and other resources in parallel.