Update .openpublishing.publish.config.json (#475) (#476)

Updating PDF functionality

Author: TaraMeyer

.openpublishing.publish.config.json

@@ -46,13 +46,23 @@
       "url": "https://github.com/MicrosoftDocs/dotnet-xref",
       "branch": "live",
       "branch_mapping": {}
+    },
+    {
+    "path_to_root": "_themes.pdf",
+    "url": "https://github.com/Microsoft/templates.docs.msft.pdf",
+    "branch": "master"
     }
   ],
   "branch_target_mapping": {
     "live": [
       "Publish",
       "Pdf"
     ]
+  },
+   "Targets": {  
+    "Pdf": {  
+    "template_folder": "_themes.pdf"  
+    }  
   },
   "need_generate_pdf_url_template": true,
   "need_generate_intellisense": false,
@@ -75,4 +85,4 @@
     "mapping/monikerMapping.json"
   ],
   "dest": "_site"
-}
+}