docs: Add Atom feed for Releases (#87)

Author: pomstazlesa

content/FAQ.md

@@ -223,6 +223,8 @@ To subscribe to release notifications, on the secureblue GitHub page, click "Wat
 
 <img alt="GitHub screenshot" src="/assets/release-notifications.png" />
 
+If you prefer to use an Atom feed, supported by many RSS clients, you can use the [feed provided by GitHub](https://github.com/secureblue/secureblue/releases.atom).
+
 ### [Why don't my AppImages work?](#appimage)
 {: #appimage}