Update CHANGELOG.md to include #2611

CHANGELOG.md

@@ -17,6 +17,7 @@ Add delegation support for Subnet #
 * Data Source:  `azurerm_public_ip` - now exports `location`, `sku`, `allocation_method`, `reverse_fqdn` and `zones` [GH-2576]
 * `azurerm_app_service` - exporting the `possible_outbound_ip_addresses` [GH-2513]
 * `azurerm_firewall` - renaming the `public_ip_address_id` property to `ip_address_id` [GH-2433]
+* `azurerm_kubernetes_cluster` - the `dns_prefix` now forces a new resource and is properly validated [GH-2611]
 * `azurerm_log_analytics_workspace_linked_service` - now correctly handels uppcase `workspace_name` values  [GH-2594]
 * `azurerm_network_interface` - support for IPv6 addresses [GH-2548]
 * `azurerm_policy_assignment` - support for Managed Service Identity [GH-2549]