add docs for feature gate

Author: mwhittington21

docs/deploy/configurations.md

@@ -189,3 +189,4 @@ There are a set of key=value pairs that describe AWS load balancer controller fe
 | LBCapacityReservation | string | true | Enable or disable the capacity reservation feature on ALB and NLB |
 | EnableTCPUDPListenerType | string | false | Enable or disable creation of TCP_UDP type listeners. This value can be overriden at the Service level by the annotation `service.beta.kubernetes.io/aws-load-balancer-enable-tcp-udp-listener` |
 | EnhancedDefaultBehavior | string | false | Enable this feature to allow the controller to remove Provisioned Capacity or mTLS settings by removing the corresponding annotation. |
+| EnableDefaultTagsLowPriority | string | false | If enabled, tags supplied via `--default-tags` will be overridden by tags specified in other manners, like via annotations. |