add the GroundPrimitiveLayer

modules/layer/index.js

@@ -15,6 +15,7 @@ export { default as CzmlLayer } from './type/CzmlLayer'
 export { default as DynamicLayer } from './type/DynamicLayer'
 export { default as FeatureGridLayer } from './type/FeatureGridLayer'
 export { default as GeoJsonLayer } from './type/GeoJsonLayer'
+export { default as GroundPrimitiveLayer } from './type/GroundPrimitiveLayer'
 export { default as HtmlLayer } from './type/HtmlLayer'
 export { default as KmlLayer } from './type/KmlLayer'
 export { default as LabelLayer } from './type/LabelLayer'