Add website documentation

website/docs/r/api_management.html.markdown

@@ -81,6 +81,10 @@ The following arguments are supported:
 
 * `sign_up` - (Optional) A `sign_up` block as defined below.
 
+* `virtual_network_type` - (Optional) The type of virtual network you want to use, valid values include: `None`, `External`, `Internal`.
+
+* `virtual_network_configuration` - (Optional) A `virtual_network_configuration` block as defined below. Required when `virtual_network_type` is `External` or `Internal`.
+
 * `tags` - (Optional) A mapping of tags assigned to the resource.
 
 ---
@@ -256,6 +260,12 @@ A `sign_up` block supports the following:
 
 ---
 
+A `virtual_network_configuration` block supports the following:
+
+* `subnet_id` - (Required) The id of the subnet that will be used for the API Management.
+
+---
+
 A `terms_of_service` block supports the following:
 
 * `consent_required` - (Required) Should the user be asked for consent during sign up?