feat: Introduce activationThreshold/minMetricValue for Kafka Scaler (k…

…edacore#865)

content/docs/2.8/scalers/apache-kafka.md

@@ -28,6 +28,7 @@ triggers:
     consumerGroup: my-group
     topic: test-topic
     lagThreshold: '5'
+    activationLagThreshold: '3'
     offsetResetPolicy: latest
     allowIdleConsumers: false
     scaleToZeroOnInvalidOffset: false
@@ -40,6 +41,7 @@ triggers:
 - `consumerGroup` - Name of the consumer group used for checking the offset on the topic and processing the related lag.
 - `topic` - Name of the topic on which processing the offset lag. (Optional, see note below)
 - `lagThreshold` - Average target value to trigger scaling actions. (Default: `5`, Optional)
+- `activationLagThreshold` - Target value for activating the scaler. Learn more about activation [here](./../concepts/scaling-deployments.md#activating-and-scaling-thresholds).(Default: `0`, Optional)
 - `offsetResetPolicy` - The offset reset policy for the consumer. (Values: `latest`, `earliest`, Default: `latest`, Optional)
 - `allowIdleConsumers` - When set to `true`, the number of replicas can exceed the number of
 partitions on a topic, allowing for idle consumers. (Default: `false`, Optional)