Deprecate Dynamic Links (#75)

Author: morganchen12

dynamic_links/README.md

@@ -1,6 +1,11 @@
 Firebase Dynamic Links Quickstart
 ==============================
 
+> [!IMPORTANT]
+> Firebase Dynamic Links is **deprecated** and should not be used in new projects. The service will shut down on August 25, 2025.
+>
+> Please see our [Dynamic Links Deprecation FAQ documentation](https://firebase.google.com/support/dynamic-links-faq) for more guidance.
+
 Introduction
 ------------