add inputs in README

Author: Guimove

README.md

@@ -54,10 +54,44 @@ module "bastion" {
   }
 }
 ```
+## Inputs
+
+| Name | Description | Type | Default | Required |
+|------|-------------|:----:|:-----:|:-----:|
+| auto_scaling_group_subnets | List of subnet were the Auto Scalling Group will deploy the instances | list | - | yes |
+| bastion_amis |  | map | `<map>` | no |
+| bastion_host_key_pair | Select the key pair to use to launch the bastion host | string | - | yes |
+| bastion_instance_count |  | string | `1` | no |
+| bastion_record_name | DNS record name to use for the bastion | string | `` | no |
+| bucket_name | Bucket name were the bastion will store the logs | string | - | yes |
+| cidrs | List of CIDRs than can access to the bastion. Default : 0.0.0.0/0 | list | `<list>` | no |
+| create_dns_record | Choose if you want to create a record name for the bastion (LB). If true 'hosted_zone_name' and 'bastion_record_name' are mandatory | string | - | yes |
+| elb_subnets | List of subnet were the ELB will be deployed | list | - | yes |
+| hosted_zone_name | Name of the hosted zone were we'll register the bastion DNS name | string | `` | no |
+| is_lb_private | If TRUE the load balancer scheme will be "internal" else "internet-facing" | string | - | yes |
+| log_auto_clean | Enable or not the lifecycle | string | `false` | no |
+| log_expiry_days | Number of days before logs expiration | string | `90` | no |
+| log_glacier_days | Number of days before moving logs to Glacier | string | `60` | no |
+| log_standard_ia_days | Number of days before moving logs to IA Storage | string | `30` | no |
+| region |  | string | - | yes |
+| tags | A mapping of tags to assign | map | `<map>` | no |
+| vpc_id | VPC id were we'll deploy the bastion | string | - | yes |
+
+## Outputs
+
+| Name | Description |
+|------|-------------|
+| bucket_name |  |
+| elb_ip |  |
+
 
 Known issues
 ------------
 
+Tags are not applied to the instances generated by the auto scaling group.
+Known terraform issue : terraform-providers/terraform-provider-aws#290
+
+
 Authors
 -------