DOCSP-45316 c2c backport file (#482)

* DOCSP-45316 c2c backport file

* *

* syntax

* correction

Author: ajhuh-mdb

.backportrc.json

@@ -0,0 +1,14 @@
+{
+    "repoOwner": "mongodb",
+    "repoName": "docs-cluster-to-cluster-sync",
+  
+    "targetBranchChoices": ["master", "v1.9", "v1.8"],
+  
+    "editor": "code",
+  
+    "maxNumber": 15,
+  
+    "backportBranchName": "{{sourcePullRequest.title}}-{{targetBranch}}-backport",
+  
+    "prTitle": "{{sourcePullRequest.title}}-{{targetBranch}}-backport ({{sourcePullRequest.number}})"
+}