chore: update doc links from googleapis.dev to cloud.google.com (#93)

Author: dandhlee

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

@@ -2,7 +2,7 @@
     "name": "domains",
     "name_pretty": "Cloud Domains",
     "product_documentation": "https://cloud.google.com/domains",
-    "client_documentation": "https://googleapis.dev/python/domains/latest",
+    "client_documentation": "https://cloud.google.com/python/docs/reference/domains/latest",
     "issue_tracker": "",
     "release_level": "beta",
     "language": "python",