aws_docdbelastic_cluster: update documentation

website/docs/r/docdbelastic_cluster.html.markdown

@@ -41,9 +41,10 @@ The following arguments are required:
 
 The following arguments are optional:
 
+* `backup_retention_period` - (Optional) The number of days for which automatic snapshots are retained. It should be in between 1 and 35. If not specified, the default value of 1 is set.
 * `kms_key_id` - (Optional) ARN of a KMS key that is used to encrypt the Elastic DocumentDB cluster. If not specified, the default encryption key that KMS creates for your account is used.
+* `preferred_backup_window` - (Optional) The daily time range during which automated backups are created if automated backups are enabled, as determined by the `backup_retention_period`.
 * `preferred_maintenance_window` - (Optional) Weekly time range during which system maintenance can occur in UTC. Format: `ddd:hh24:mi-ddd:hh24:mi`. If not specified, AWS will choose a random 30-minute window on a random day of the week.
-* `backup_retention_period` - (Optional) The number of days for which automatic snapshots are retained. It should be in between 1 and 35. If not specified, the default value of 1 is set.
 * `subnet_ids` - (Optional) IDs of subnets in which the Elastic DocumentDB Cluster operates.
 * `tags` - (Optional) A map of tags to assign to the collection. If configured with a provider [`default_tags` configuration block](https://registry.terraform.io/providers/hashicorp/aws/latest/docs#default_tags-configuration-block) present, tags with matching keys will overwrite those defined at the provider-level.
 * `vpc_security_group_ids` - (Optional) List of VPC security groups to associate with the Elastic DocumentDB Cluster