fix broken link

Author: flang-msft

articles/azure-cache-for-redis/cache-how-to-zone-redundancy.md

@@ -74,7 +74,7 @@ To create a cache, follow these steps:
 
 - [Why can't I enable zone redundancy when creating a Premium cache?](#why-cant-i-enable-zone-redundancy-when-creating-a-premium-cache)
 - [Why can't I select all three zones during cache create?](#why-cant-i-select-all-three-zones-during-cache-create)
-- Can I update my existing Standard or Premium cache to use zone redundancy?]
+- [Can I update my existing Standard or Premium cache to use zone redundancy?](#can-i-update-my-existing-standard-or-premium-cache-to-use-zone-redundancy)
 - [How much does it cost to replicate my data across Azure Availability Zones?](#how-much-does-it-cost-to-replicate-my-data-across-azure-availability-zones)
 
 ### Why can't I enable zone redundancy when creating a Premium cache?