message: Simplify code snippet in README.md
  Remove the default parameters from the initialization of
  the `OmvDataSource`.
diff: @@ -72,13 +72,7 @@ const map = new harp.MapView({
  const controls = new harp.MapControls(map);
  const omvDataSource = new harp.OmvDataSource({
  baseUrl: "https://vector.hereapi.com/v2/vectortiles/base/mc",
  - apiFormat: harp.APIFormat.XYZOMV,
  - styleSetName: "tilezen",
  - authenticationCode: "YOUR-APIKEY",
  - authenticationMethod: {
  - method: harp.AuthenticationMethod.QueryString,
  - name: "apikey"
  - }
  + authenticationCode: "YOUR-APIKEY"
  });
  map.addDataSource(omvDataSource);
  ```
  