Mark ActionCodeSettings.dynamicLinkDomain as deprecated

Author: NhienLam

docs-devsite/auth.actioncodesettings.md

@@ -47,6 +47,11 @@ android?: {
 
 ## ActionCodeSettings.dynamicLinkDomain
 
+> Warning: This API is now obsolete.
+> 
+> Firebase Dynamic Links is deprecated. Migrate to use Firebase Hosting link and use `linkDomain` to set a custom domain instead.
+> 
+
 When multiple custom dynamic link domains are defined for a project, specify which one to use when the link is to be opened via a specified mobile app (for example, `example.page.link`<!-- -->).
 
 <b>Signature:</b>

packages/auth/src/model/public_types.ts

@@ -513,6 +513,9 @@ export interface ActionCodeSettings {
    *
    *
    * @defaultValue The first domain is automatically selected.
+   *
+   * @deprecated Firebase Dynamic Links is deprecated. Migrate to use Firebase Hosting link and use
+   * `linkDomain` to set a custom domain instead.
    */
   dynamicLinkDomain?: string;
   /**