Add WAF definition

Author: hemraker

umbraco-cloud/release-notes/overview-2025/2025-09-03-releasenotes.md

@@ -13,7 +13,7 @@
 Pre-validating hostnames allows you to prepare domains before pointing DNS to Umbraco Cloud. This ensures TLS certificates are issued and routing is active ahead of time, so projects can go live instantly once DNS is updated.
 
 * **Zero-downtime hostname migration** – Move production domains to Umbraco Cloud without service interruptions.
-* **On-premise proxy support** – Keep using your existing proxy or WAF setup while preparing hostnames in Umbraco Cloud.
+* **On-premise proxy support** – Keep using your existing proxy or Web Application Firewall (WAF) setup while preparing hostnames in Umbraco Cloud.
 
 <figure><img src="../../go-live/manage-hostnames/images/pre-validation-status-modal.png" alt="This is a screenshot of the Pre-Validation status modal"></figure>