readme fix for exampl of primary origin and s3 bucket failover

README.md

@@ -156,15 +156,15 @@ module "cdn" {
   aliases           = ["assets.cloudposse.com"]
   dns_alias_enabled = true
   parent_zone_name  = "cloudposse.com"
-  s3_origins = {
+  s3_origins = [{
     domain_name = module.s3_bucket.bucket_regional_domain_name
     origin_id   = module.s3_bucket.bucket_id
     origin_path = null
     s3_origin_config = {
       origin_access_identity = null # will get translated to the origin_access_identity used by the origin created by this module.
     }
-  }
-  origin_groups = {
+  }]
+  origin_groups = [{
     primary_origin_id  = null # will get translated to the origin id of the origin created by this module.
     failover_origin_id = module.s3_bucket.bucket_id
     failover_criteria  = [
@@ -173,7 +173,7 @@ module "cdn" {
       500,
       502
     ]
-  }
+  }]
 }
 ```