Add link to new MSRC portal (dotnet#19236)

* Add link to new MSRC portal

* Update SECURITY.md

Co-authored-by: Pranav K <[email protected]>

Author: blowdart

SECURITY.md

@@ -6,9 +6,9 @@ The .NET Core and ASP.NET Core support policy, including supported versions can
 
 ## Reporting a Vulnerability
 
-Security issues and bugs should be reported privately, via email, to the Microsoft Security Response Center (MSRC) [email protected]. 
+Security issues and bugs should be reported privately, via email, to the Microsoft Security Response Center (MSRC) through https://msrc.microsoft.com or by emailing [email protected]. 
 You should receive a response within 24 hours. If for some reason you do not, please follow up via email to ensure we received your 
-original message. Further information, including the MSRC PGP key, can be found in the [Security TechCenter](https://technet.microsoft.com/en-us/security/ff852094.aspx).
+original message. Further information, including the MSRC PGP key, can be found in the [MSRC Report an Issue FAQ](https://www.microsoft.com/en-us/msrc/faqs-report-an-issue).
 
 Reports via MSRC may qualify for the .NET Core Bug Bounty. Details of the .NET Core Bug Bounty including terms and conditions are at [https://aka.ms/corebounty](https://aka.ms/corebounty).