chore(nodejs): update client ref docs link in metadata (#472)

Author: fhinkel

packages/google-cloud-dns/.repo-metadata.json

@@ -2,7 +2,7 @@
   "name": "dns",
   "name_pretty": "Cloud DNS",
   "product_documentation": "https://cloud.google.com/dns",
-  "client_documentation": "https://googleapis.dev/nodejs/dns/latest",
+  "client_documentation": "https://cloud.google.com/nodejs/docs/reference/dns/latest",
   "issue_tracker": "https://issuetracker.google.com/savedsearches/559772",
   "release_level": "ga",
   "language": "nodejs",

packages/google-cloud-dns/README.md

@@ -146,7 +146,7 @@ Apache Version 2.0
 
 See [LICENSE](https://github.com/googleapis/nodejs-dns/blob/master/LICENSE)
 
-[client-docs]: https://googleapis.dev/nodejs/dns/latest
+[client-docs]: https://cloud.google.com/nodejs/docs/reference/dns/latest
 [product-docs]: https://cloud.google.com/dns
 [shell_img]: https://gstatic.com/cloudssh/images/open-btn.png
 [projects]: https://console.cloud.google.com/project