add Basic policy

Author: vhorne

articles/firewall-manager/policy-overview.md

@@ -37,13 +37,14 @@ Azure Firewall supports both Classic rules and policies, but policies is the rec
 |Pricing     |Billed based on firewall association. See [Pricing](#pricing).|Free|
 |Supported deployment mechanisms     |Portal, REST API, templates, Azure PowerShell, and CLI|Portal, REST API, templates, PowerShell, and CLI. |
 
-## Standard and Premium policies
+## Basic, Standard, and Premium policies
 
-Azure Firewall supports Standard and Premium policies. The following table summarizes the difference between the two:
+Azure Firewall supports Basic (preview) Standard, and Premium policies. The following table summarizes the difference between these policies:
 
 
 |Policy type|Feature support  | Firewall SKU support|
 |---------|---------|----|
+|Basic policy|NAT rules, Application rules<br>IP Groups<br>Threat Intelligence (alerts)|Basic
 |Standard policy    |NAT rules, Network rules, Application rules<br>Custom DNS, DNS proxy<br>IP Groups<br>Web Categories<br>Threat Intelligence|Standard or Premium|
 |Premium policy    |All Standard feature support, plus:<br><br>TLS Inspection<br>Web Categories<br>URL Filtering<br>IDPS|Premium