Update prereqs for Azure AD Connect with link

Author: Brenduns

memdocs/intune/protect/includes/security-config-mgt-prerequisites.md

@@ -28,9 +28,10 @@ When a device that is domain joined creates a trust with Azure Active Directory,
 - Azure Active Directory Connect (AAD Connect) must be synchronized to the tenant that is used from Microsoft Defender for Endpoint
 - Hybrid Azure Active Directory Join must be configured in your environment (either through Federation or AAD Connect Sync)
 - AAD Connect Sync must include the device objects *in scope* for synchronization with Azure Active Directory (when needed for join)
-- AAD Connect rules for sync must be modified for Server 2012 R2 (when support for Server 2012 R2 is needed)
+- AAD Connect rules for sync [must be modified for Server 2012 R2](/microsoft-365/security/defender-endpoint/troubleshoot-security-config-mgt?view=o365-worldwide#instructions-for-applying-computer-join-rule-in-aad-connect) (when support for Server 2012 R2 is needed)
 - All devices must register in the Azure Active Directory of the tenant that hosts Microsoft Defender for Endpoint. Cross-tenant scenarios are not supported.
 
+
 ### Connectivity requirements
 
 Devices must have access to the following endpoints: