doc: add coverage badges.

Author: jaywcjlove

README.md

@@ -1,7 +1,7 @@
 react-only-when
 ===
 
-[![Build & Deploy](https://github.com/uiwjs/react-only-when/actions/workflows/ci.yml/badge.svg)](https://github.com/uiwjs/react-only-when/actions/workflows/ci.yml) [![npm bundle size](https://img.shields.io/bundlephobia/minzip/@uiw/react-only-when)](https://www.npmjs.com/package/@uiw/react-only-when) [![npm version](https://img.shields.io/npm/v/@uiw/react-md-editor.svg)](https://www.npmjs.com/package/@uiw/react-md-editor)
+[![Build & Deploy](https://github.com/uiwjs/react-only-when/actions/workflows/ci.yml/badge.svg)](https://github.com/uiwjs/react-only-when/actions/workflows/ci.yml) [![npm bundle size](https://img.shields.io/bundlephobia/minzip/@uiw/react-only-when)](https://www.npmjs.com/package/@uiw/react-only-when) [![npm version](https://img.shields.io/npm/v/@uiw/react-md-editor.svg)](https://www.npmjs.com/package/@uiw/react-md-editor) [![Coverage Status](https://coveralls.io/repos/github/uiwjs/react-only-when/badge.svg?branch=main)](https://coveralls.io/github/uiwjs/react-only-when?branch=main)
 
 A declarative component for conditional rendering. Copy [`react-only-when`](https://github.com/sag1v/react-only-when), let it support TypeScript.
 

website/index.tsx

@@ -1,4 +1,3 @@
-import React from 'react';
 import ReactDOM from 'react-dom';
 import MarkdownPreview from '@uiw/react-markdown-preview';
 import GitHubCorners from '@uiw/react-github-corners';