【更新】README.en.md

[shaoguoji]

No description provided.

[shaoguoji]

/check-cla

[rtthread-bot]

感谢提交 Pull Requests ！
在我们查看您的 Pull Requests 之前，您需要签署《贡献者许可协议（CLA）》。
请按照 https://www.rt-thread.org/cla/ 页面提示步骤操作，完成 CLA 签署。之后新增评论 /check-cla，我们将再次检查协议签署情况。

• 如果您已签署 CLA 且仍然出现此提示，请在 Github 账号个人页面 https://github.com/settings/emails 确认已绑定邮箱并验证，同时与签署页面填写的邮箱一致。
• 若您完成以上步骤后，依然显示 CLA 未签署信息，请发邮件联系我们，邮箱地址：contact@rt-thread.org。

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Thanks for your pull request.
Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).
Please follow instructions at https://www.rt-thread.org/cla/ to sign the CLA.
It may take a couple minutes for the CLA signature to be fully registered;
after that, please reply here with a new comment /check-cla and we'll verify.

• If you've already signed a CLA, it's possible we don't have your Github username or you're using a different email address.
  Check your existing CLA data and verify that your email at https://github.com/settings/emails.
• If you have done the above and are still having issues with the CLA being reported as unsigned,
  send a message to the backup e-mail support address at: contact@rt-thread.org