doc: update README

README.md

@@ -1,2 +1,33 @@
 # terraform-aws-secure-baseline
-A terraform module to set up your AWS account with reasonably secure configurations.
+
+[Terraform Module Registry](https://registry.terraform.io/modules/nozaq/secure-baseline/aws)
+
+A terraform module to set up your AWS account with the reasonably secure configuration baseline.
+Most configurations are based on [CIS Amazon web Services Foundations].
+
+## Features
+
+- Set up IAM Password Policy.
+- Enable CloudTrail with KMS encryption in all regions and deliver events to CloudWatch Logs.
+- Enable AWS Config in all regions to automatically take configuration snapshots.
+- All logs are stored in the S3 bucket with access logging enabled.
+- Set up CloudWatch alarms to notify you when critical changes happen in your AWS account.
+- Enable VPC Flow Logs with the default VPC in all regions.
+- Remove all rules in default route tables, default network ACLs and default security groups in the default VPC in all regions.
+
+## Usage
+
+```hcl
+data "aws_caller_identity" "current" {}
+data "aws_region" "current" {}
+
+module "secure-baseline" {
+  source  = "nozaq/secure-baseline/aws"
+
+  audit_log_bucket_name = "YOUR_BUCKET_NAME"
+  aws_account_id = "${data.aws_caller_identity.current.account_id}"
+  region = "${data.aws_region.current.name}"
+}
+```
+
+[CIS Amazon Web Services Foundations]: https://d0.awsstatic.com/whitepapers/compliance/AWS_CIS_Foundations_Benchmark.pdf