Update faq.yml file to add a tip to reduce refreshtoken skew time of 5 minutes in custom policy

customers often ask on how to control the refreshtoken skew time in b2c. If they are using custom policy, it can be contolled by adjusting the "TreatAsEqualIfWithinMillseconds" value. This was recently introduced as part of RedeemRefreshToken journey and updated in latest starter packs

Author: nithinsas

articles/active-directory-b2c/faq.yml

@@ -286,6 +286,9 @@ sections:
           1. Wait for 10 minutes.
           
           1. Retrieve the `RefreshToken` again.
+
+          > [!TIP]
+          > With Azure AD B2C [custom policy](custom-policy-overview.md), you can reduce the above mentioned skew time of 5 minutes (300000 milliseconds)  by adjusting the value for InputParameter "TreatAsEqualIfWithinMillseconds" under claim transformation Id "AssertRefreshTokenIssuedLaterThanValidFromDate". This claim transformation can be found in the TrustFrameworkBase.xml file under latest custom policy [stater-pack](https://learn.microsoft.com/en-us/azure/active-directory-b2c/tutorial-create-user-flows?pivots=b2c-custom-policy#get-the-starter-pack). 
           
       - question: |
          I use multiple tabs in a web browser to sign in to multiple applications that I registered in the same Azure AD B2C tenant. When I try to perform a single sign-out, not all of the applications are signed out. Why does this happen?