message: Update API-reference.md
  Closes
diff: @@ -126,6 +126,18 @@ Parameter | Type | Description
  `duration?` | number | **Optional**<br>Elapsed time of request & reply
  `method?` | string | **Optional**<br>Represents request verb (GET, POST, etc.)
  +### trackEvent
  +
  +```ts
  +applicationInsights.trackEvent(event: IEventTelemetry, customProperties?: { [key: string]: any })
  +```
  +
  +The `IEventTelemetry` interface is below:
  +
  +Parameter | Type | Description
  +---|---|---
  +`name` | string | **Required**<br>An event name string.
  +
  ### flush
  ```ts
  