All: Add docs job to publish to googleapis.dev. (#8464)

Author: busunkim96

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

@@ -0,0 +1,12 @@
+{
+  "name": "dns",
+  "name_pretty": "Cloud DNS",
+  "product_documentation": "https://cloud.google.com/dns",
+  "client_documentation": "https://googleapis.dev/python/dns/latest",
+  "issue_tracker": "https://issuetracker.google.com/savedsearches/559772",
+  "release_level": "alpha",
+  "language": "python",
+  "repo": "googleapis/google-cloud-python",
+  "distribution_name": "google-cloud-dns",
+  "requires_billing": true
+}