Fix docs

Author: jiaweitao001

website/docs/r/virtual_network_gateway.html.markdown

@@ -148,13 +148,13 @@ The following arguments are supported:
 
 * `max_scale_unit` - (Optional) The maximum scale unit for the Virtual Network Gateway, possible values are `1` through `40`. 
 
-~> `max_scale_unit` is only supported for the `ErGwScale` SKU.
+~> **Note:** `max_scale_unit` is only supported for the `ErGwScale` SKU.
 
 * `min_scale_unit` - (Optional) The minimum scale unit for the Virtual Network Gateway, possible values are `1` through `40`. 
 
-~> `min_scale_unit` is only supported for the `ErGwScale` SKU.
+~> **Note:** `min_scale_unit` is only supported for the `ErGwScale` SKU.
 
-~> To configure a `fixed-size` gateway, set `min_scale_unit` and `max_scale_unit` to the same value. To enable `autoscaling`, set `min_scale_unit` to `2` or higher and `max_scale_unit` up to `40`. When `max_scale_unit` is set to `1`, `min_scale_unit` must also be set to `1`.
+~> **Note:** To configure a `fixed-size` gateway, set `min_scale_unit` and `max_scale_unit` to the same value. To enable `autoscaling`, set `min_scale_unit` to `2` or higher and `max_scale_unit` up to `40`. When `max_scale_unit` is set to `1`, `min_scale_unit` must also be set to `1`.
 
 * `policy_group` - (Optional) One or more `policy_group` blocks as defined below.