Docs: fixed naming

README.md

@@ -56,7 +56,7 @@ The deployment script uses a configuration class `GraphDeployerConfiguration` to
         {
           "Name": "RepositoryName",
           "Url": "https://gitlab.example.com/group/project.git",
-          "Branch": "main"
+          "Ref": "main"
         }
       ]
     }