DOC-1391: Add link to Active-Active application failover page in Auto Tiering index

Author: mich-elle-luna

content/operate/rs/databases/auto-tiering/_index.md

@@ -104,6 +104,8 @@ On-premises environments support more deployment options than other environments
   - [Time series]({{< relref "/operate/oss_and_stack/stack-with-enterprise/timeseries" >}})
   - [Probabilistic data structures]({{< relref "/operate/oss_and_stack/stack-with-enterprise/bloom" >}})
 
+For more information about application failover with Active-Active databases, see [Application failover with Active-Active databases]({{< relref "/operate/rs/databases/active-active/develop/app-failover-active-active.md" >}}).
+
 {{<note>}} Enabling Auto Tiering for Active-Active distributed databases requires validating and getting the Redis technical team's approval first . {{</note>}}
 
 {{<warning>}} Auto Tiering is not supported running on network attached storage (NAS), storage area network (SAN), or with local HDD drives. {{</warning>}}