message: Add missing loadAppInsights to README
diff: @@ -48,6 +48,7 @@ const appInsights = new ApplicationInsights({ config: {
  extensions: [customPlugin],
  /* ...Other Configuration Options... */
  }});
  +appInsights.loadAppInsights();
  ```
  ### Snippet Setup (Ignore if using NPM)
  @@ -213,6 +214,7 @@ const appInsights = new ApplicationInsights({ config: {
  extensions: [customPlugin],
  // Other Configuration Options...
  }});
  +appInsights.loadAppInsights();
  ```
  ITelemetryPlugin has a simpler base type IPlugin that you can instantiate for initialization purposes when SDK loads.
  