Updated README.md after merge

Author: antonbabenko

README.md

@@ -167,7 +167,7 @@ Terraform version 0.10.3 or newer is required for this module to work.
 
 | Name | Description | Type | Default | Required |
 |------|-------------|:----:|:-----:|:-----:|
-| amazon_side_asn | The Autonomous System Number (ASN) for the Amazon side of the gateway. If you don't specify an ASN, the virtual private gateway is created with the default ASN. | string | `` | no |
+| amazon_side_asn | The Autonomous System Number (ASN) for the Amazon side of the gateway. By default the virtual private gateway is created with the current default Amazon ASN. | string | `64512` | no |
 | assign_generated_ipv6_cidr_block | Requests an Amazon-provided IPv6 CIDR block with a /56 prefix length for the VPC. You cannot specify the range of IP addresses, or the size of the CIDR block | string | `false` | no |
 | azs | A list of availability zones in the region | string | `<list>` | no |
 | cidr | The CIDR block for the VPC. Default value is a valid CIDR, but not acceptable by AWS and should be overridden | string | `0.0.0.0/0` | no |