Update .openpublishing.publish.config.json

.openpublishing.publish.config.json

@@ -23,6 +23,7 @@
       "customized_tasks": {
         "docset_prebuild": [
           "_dependentPackages/CommonPlugins/tools/JoinTOC.ps1",
+          "_dependentPackages/CommonPlugins/tools/SplitTOC.ps1",
           "_dependentPackages/CommonPlugins/tools/DiffFolder.ps1"
         ]
       },
@@ -80,6 +81,10 @@
       "version": "latest"
     }
   ],
+  "SplitTOC": [
+    "docs-ref-autogen/toc.yml",
+    "preview/docs-ref-autogen/toc.yml"
+  ],
   "JoinTOCPlugin": [
     {
       "TopLevelTOC": "docs-ref-mapping/reference.yml",