(MODULES-1702) Update README with example

README.md

@@ -224,6 +224,27 @@ elb_loadbalancer { 'name-of-load-balancer':
 }
 ```
 
+### rds_instance
+
+```puppet
+rds_instance { 'db-name':
+  ensure => present,
+  region => 'us-west-1',
+  db_name => 'db-name',
+  engine => 'mysql',
+  engine_version => '5.6.19a',
+  license_model => 'general-public-license',
+  allocated_storage => 10,
+  availability_zone_name => 'us-west-1a',
+  storage_type => 'gp2',
+  db_instance_class => 'db.t2.micro',
+  master_username => 'master-db-user',
+  master_user_password => 'the-master-password',
+  multi_az => false,
+  db_subnet_group_name => 'name-of-VPC',
+}
+```
+
 ##Limitations
 
 At the moment this module only supports a small number of the resources