Update heading level for job skills section

Author: staleycyn

Instructions/Exercises/M02-Unit 7 Create a Virtual WAN by using Azure Portal.md

@@ -12,7 +12,7 @@ In this exercise, you will create a Virtual WAN for Contoso.
 
 ![Diagram of virtual network WAN architecture.](../media/7-exercise-create-virtual-wan-by-using-azure-portal.png)
 
-### Job skills
+## Job skills
 In this exercise, you will:
 
 + Task 1: Create a Virtual WAN