Update pi_network documentation to provide information about default DNS configurations

website/docs/r/pi_network.html.markdown

@@ -1,5 +1,4 @@
 ---
-
 subcategory: "Power Systems"
 layout: "ibm"
 page_title: "IBM: pi_network"
@@ -8,9 +7,11 @@ description: |-
 ---
 
 # ibm_pi_network
+
 Create, update, or delete a network connection for your Power Systems Virtual Server instance. For more information, about power virtual server instance network, see [setting up an IBM i network install server](https://cloud.ibm.com/docs/power-iaas?topic=power-iaas-preparing-install-server).
 
 ## Example usage
+
 The following example creates a network connection for your Power Systems Virtual Server instance.
 
 ```terraform
@@ -30,11 +31,13 @@ resource "ibm_pi_network" "power_networks" {
 ```
 
 **Note**
-* Please find [supported Regions](https://cloud.ibm.com/apidocs/power-cloud#endpoint) for endpoints.
-* If a Power cloud instance is provisioned at `lon04`, The provider level attributes should be as follows:
-  * `region` - `lon`
-  * `zone` - `lon04`
-
+
+- Please find [supported Regions](https://cloud.ibm.com/apidocs/power-cloud#endpoint) for endpoints.
+- If a Power cloud instance is provisioned at `lon04`, The provider level attributes should be as follows:
+
+  - `region` - `lon`
+  - `zone` - `lon04`
+
   Example usage:
 
   ```terraform
@@ -52,29 +55,32 @@ The `ibm_pi_network` provides the following [Timeouts](https://www.terraform.io/
 - **update** - (Default 60 minutes) Used for updating a network.
 - **delete** - (Default 60 minutes) Used for deleting a network.
 
-## Argument reference 
-Review the argument references that you can specify for your resource. 
+## Argument reference
+
+Review the argument references that you can specify for your resource.
 
 - `pi_cloud_instance_id` - (Required, String) The GUID of the service instance associated with an account.
 - `pi_network_name` - (Required, String) The name of the network.
 - `pi_network_type` - (Required, String) The type of network that you want to create, such as `pub-vlan` or `vlan`.
-- `pi_dns` - (Optional, Set of String) The DNS Servers for the network. Required for `vlan` network type.
+- `pi_dns` - (Optional, Set of String) The DNS Servers for the network. If not specified, default is 127.0.0.1 for 'vlan' (private network) and 9.9.9.9 for 'pub-vlan' (public network)
 - `pi_cidr` - (Optional, String) The network CIDR. Required for `vlan` network type.
 - `pi_gateway` - (Optional, String) The gateway ip address.
-- `pi_ipaddress_range` - (Optional, List of Map) List of one or more ip address range. The `pi_ipaddress_range` object structure is documented below. 
+- `pi_ipaddress_range` - (Optional, List of Map) List of one or more ip address range. The `pi_ipaddress_range` object structure is documented below.
   The `pi_ipaddress_range` block supports:
   - `pi_ending_ip_address` - (Required, String) The ending ip address.
   - `pi_starting_ip_address` - (Required, String) The staring ip address. **Note** if the `pi_gateway` or `pi_ipaddress_range` is not provided, it will calculate the value based on CIDR respectively.
 - `pi_network_jumbo` - (Optional, Bool) MTU Jumbo option of the network.
 
 ## Attribute reference
+
 In addition to all argument reference list, you can access the following attribute reference after your resource is created.
 
 - `id` - (String) The unique identifier of the network. The ID is composed of `<power_instance_id>/<network_id>`.
 - `network_id` - (String) The unique identifier of the network.
-- `vlan_id` - (Integer) The ID of the VLAN that your network is attached to. 
+- `vlan_id` - (Integer) The ID of the VLAN that your network is attached to.
 
 ## Import
+
 The `ibm_pi_network` resource can be imported by using `power_instance_id` and `network_id`.
 
 **Example**