Initialize open publishing repository: https://github.com/MicrosoftDocs/office-docs-powershell of branch live

Author: saldana

.openpublishing.publish.config.json

@@ -120,7 +120,8 @@
   "notification_subscribers": [],
   "branches_to_filter": [],
   "skip_source_output_uploading": false,
-  "need_preview_pull_request": false,
+  "need_preview_pull_request": true,
+  "contribution_branch_mappings": {},
   "dependent_repositories": [
     {
       "path_to_root": "_themes",