fix issues

Author: AlisherAmonulloev

React/src/App.tsx

@@ -1,4 +1,4 @@
-import React, { useCallback } from 'react';
+import { useCallback } from 'react';
 import './App.css';
 import 'devextreme/dist/css/dx.material.blue.light.compact.css';
 import DataGrid, {

Readme.md

@@ -21,7 +21,7 @@ In the event handler, do the following:
 
 - Add the "edit", "insert", and "delete" items to the [e.items](https://js.devexpress.com/Documentation/ApiReference/UI_Components/dxContextMenu/Configuration/items/) array. 
 
-- For each item, specify [text](https://js.devexpress.com/Documentation/ApiReference/UI_Components/dxContextMenu/Configuration/items/#text) and handle the [onItemClick](https://js.devexpress.com/Documentation/ApiReference/UI_Widgets/dxContextMenu/Configuration/#onItemClick) event. 
+- For each item, specify [text](https://js.devexpress.com/jQuery/Documentation/ApiReference/UI_Components/dxContextMenu/Configuration/items/#text) and handle the [onItemClick](https://js.devexpress.com/Documentation/ApiReference/UI_Widgets/dxContextMenu/Configuration/#onItemClick) event. 
 
 - In the corresponding **onItemClick** event handler, call the [editRow](https://js.devexpress.com/Documentation/ApiReference/UI_Widgets/dxDataGrid/Methods/#editRowrowIndex), [addRow](https://js.devexpress.com/Documentation/ApiReference/UI_Widgets/dxDataGrid/Methods/#addRow), or [deleteRow](https://js.devexpress.com/Documentation/ApiReference/UI_Widgets/dxDataGrid/Methods/#deleteRowrowIndex) methods to edit the current row, add a new row, or remove the current row.