add js

Author: artem-kurchenko

apps/demos/Demos/DataGrid/SimpleArray/ReactJs/App.js

@@ -7,7 +7,6 @@ const App = () => (
   <DataGrid
     dataSource={customers}
     keyExpr="ID"
-    defaultColumns={columns}
     showBorders={true}
   >
     {columns.map((column, index) => (