[CF4SaaS] Update external_link in regional-services-for-saas (#18918)

Author: RebeccaTamachiro

src/content/docs/cloudflare-for-platforms/cloudflare-for-saas/start/advanced-settings/regional-services-for-saas.mdx

@@ -1,7 +1,7 @@
 ---
 pcx_content_type: navigation
 title: Regional Services for SaaS
-external_link: /data-localization/regional-services/get-started/
+external_link: /data-localization/how-to/cloudflare-for-saas/
 sidebar:
   order: 2