docs(angular): add signals content (#6468)

src/data/roadmaps/angular/content/signals@u1TG8i145o0RKhOR_5epf.md

@@ -1 +1,9 @@
-# Signals
+# Signals
+
+Angular Signals is a system that granularly tracks how and where your state is used throughout an application, allowing the framework to optimize rendering updates.
+
+Visit the following resources to learn more:
+
+- [@official@Angular Official Docs - Signals](https://angular.dev/guide/signals)
+- [@video@Signals Unleashed: The Full Guide](https://www.youtube.com/watch?v=6W6gycuhiN0&t=169s)
+- [@article@Angular Signals Complete Guide](https://blog.angular-university.io/angular-signals/)