fix heading warning

Author: v-kents

articles/active-directory/authentication/howto-mfa-mfasettings.md

@@ -212,7 +212,7 @@ You can set a time period to allow authentication attempts after a user is authe
 
 Settings for app passwords, trusted IPs, verification options, and remember multi-factor authentication for Azure Multi-Factor Authentication can be found in service settings. Service settings can be accessed from the Azure portal by browsing to **Azure Active Directory** > **Security** > **MFA** > **Getting started** > **Configure** > **Additional cloud-based MFA settings**.
 
-#Add picture with public address example (I can share the picture if you want)
+## Add picture with public address example (I can share the picture if you want)
 
 The trusted IP address ranges should be the external/public IP addresses used by the caller.