Merge pull request hashicorp#1647 from terraform-providers/docs-appau…

…toscaling-policy

docs: Update appautoscaling_policy docs

website/docs/r/appautoscaling_policy.html.markdown

@@ -44,14 +44,21 @@ resource "aws_appautoscaling_policy" "ecs_policy" {
 
 The following arguments are supported:
 
-* `adjustment_type` - (Required) Specifies whether the adjustment is an absolute number or a percentage of the current capacity. Valid values are `ChangeInCapacity`, `ExactCapacity`, and `PercentChangeInCapacity`.
-* `cooldown` - (Required) The amount of time, in seconds, after a scaling activity completes and before the next scaling activity can start.
-* `metric_aggregation_type` - (Required) The aggregation type for the policy's metrics. Valid values are "Minimum", "Maximum", and "Average". Without a value, AWS will treat the aggregation type as "Average".
 * `name` - (Required) The name of the policy.
 * `policy_type` - (Optional) Defaults to "StepScaling" because it is the only option available.
 * `resource_id` - (Required) The resource type and unique identifier string for the resource associated with the scaling policy. For Amazon ECS services, this value is the resource type, followed by the cluster name and service name, such as `service/default/sample-webapp`. For Amazon EC2 Spot fleet requests, the resource type is `spot-fleet-request`, and the identifier is the Spot fleet request ID; for example, `spot-fleet-request/sfr-73fbd2ce-aa30-494c-8788-1cee4EXAMPLE`.
 * `scalable_dimension` - (Required) The scalable dimension of the scalable target. The scalable dimension contains the service namespace,   resource  type, and scaling property, such as `ecs:service:DesiredCount` for the desired task count of an Amazon ECS service, or `ec2:spot-fleet-request:TargetCapacity` for the target capacity of an Amazon EC2 Spot fleet request.
 * `service_namespace` - (Required) The AWS service namespace of the scalable target. Valid values are `ecs` for Amazon ECS services and `ec2` Amazon EC2 Spot fleet requests.
+* `step_scaling_policy_configuration` - (Optional) Step scaling policy configuration, requires `policy_type = "StepScaling"` (default). See supported fields below.
+
+## Nested fields
+
+### `step_scaling_policy_configuration`
+
+* `adjustment_type` - (Required) Specifies whether the adjustment is an absolute number or a percentage of the current capacity. Valid values are `ChangeInCapacity`, `ExactCapacity`, and `PercentChangeInCapacity`.
+* `cooldown` - (Required) The amount of time, in seconds, after a scaling activity completes and before the next scaling activity can start.
+* `metric_aggregation_type` - (Required) The aggregation type for the policy's metrics. Valid values are "Minimum", "Maximum", and "Average". Without a value, AWS will treat the aggregation type as "Average".
+* `min_adjustment_magnitude` - (Optional) The minimum number to adjust your scalable dimension as a result of a scaling activity. If the adjustment type is PercentChangeInCapacity, the scaling policy changes the scalable dimension of the scalable target by this amount.
 * `step_adjustment` - (Optional) A set of adjustments that manage scaling. These have the following structure:
 
   ```hcl