chore(nodejs): update client ref docs link in metadata (#999)

Author: fhinkel

.repo-metadata.json

@@ -2,7 +2,7 @@
   "name": "debugger",
   "name_pretty": "Stackdriver Debugger",
   "product_documentation": "https://cloud.google.com/debugger",
-  "client_documentation": "https://googleapis.dev/nodejs/debugger/latest/",
+  "client_documentation": "https://cloud.google.com/nodejs/docs/reference/debug-agent/latest",
   "issue_tracker": "https://issuetracker.google.com/savedsearches/559771",
   "release_level": "beta",
   "language": "nodejs",

README.md

@@ -125,7 +125,7 @@ Apache Version 2.0
 
 See [LICENSE](https://github.com/googleapis/cloud-debug-nodejs/blob/master/LICENSE)
 
-[client-docs]: https://googleapis.dev/nodejs/debugger/latest/
+[client-docs]: https://cloud.google.com/nodejs/docs/reference/debug-agent/latest
 [product-docs]: https://cloud.google.com/debugger
 [shell_img]: https://gstatic.com/cloudssh/images/open-btn.png
 [projects]: https://console.cloud.google.com/project