update publishednodes.json sample

opcpublisher/publishednodes.json

@@ -12,7 +12,11 @@
                 // specifies the sampling interval OPC Publisher requests the server to sample the node value
                 "OpcSamplingInterval": 2000,
                 // specifies the publishing interval OPC Publisher requests the server to publish the node value, it will only be published if the value has changed
-                "OpcPublishingInterval": 5000
+                "OpcPublishingInterval": 5000,
+                // specifies that there should be a heartbeat generated by OPC Publisher, this means that after the given interval the last message will be sent again with an updated SourceTimestamp value.
+                "Heartbeat": 3600,
+                // specifies that the first event will not generate a telemetry event, this is useful when publishing a large amount of data to prevent a event flood at startup of OPC Publisher
+                "SkipFirst":  true
             }
         ]
     },