firefox 转为「自行托管」

Author: YanhuiJessica

README.md

@@ -1,12 +1,17 @@
 <p align="center"><img width="100" alt="CUC Tronclass Courseware Downloader" src="img/tronclass-dl.jpg"></p>
 <p align="center">CUC 畅课（TronClass） <strong>课件下载</strong> 浏览器插件</p>
 
-<p align="center"><a rel="noreferrer noopener" href="https://chrome.google.com/webstore/detail/troncuclass/oekepilgaknaenpkamkpiigfndkjlmil"><img alt="Chrome Web Store" src="https://img.shields.io/badge/Chrome-141e24.svg?&style=for-the-badge&logo=google-chrome&logoColor=white&color=04acbd"></a>  <a rel="noreferrer noopener" href="https://addons.mozilla.org/zh-CN/firefox/addon/troncuclass/"><img alt="Firefox Add-ons" src="https://img.shields.io/badge/Firefox-141e24.svg?&style=for-the-badge&logo=firefox-browser&logoColor=white&color=04acbd"></a>
+<p align="center"><a rel="noreferrer noopener" href="https://chrome.google.com/webstore/detail/troncuclass/oekepilgaknaenpkamkpiigfndkjlmil"><img alt="Chrome Web Store" src="https://img.shields.io/badge/Chrome-141e24.svg?&style=for-the-badge&logo=google-chrome&logoColor=white&color=04acbd"></a>  <img alt="Firefox Add-ons" src="https://img.shields.io/badge/Firefox-141e24.svg?&style=for-the-badge&logo=firefox-browser&logoColor=white&color=04acbd">
 
 <h2 align="center">TronCUClass</h2>
 
 <p align="center">TronCUClass 支持 <strong>CUC</strong> 畅课平台上任意格式的课件下载。成功开始下载的非视频类课件，其对应在畅课平台上的进度将自动标记为已完成。</p>
 
+## Install
+
+- Chrome 用户可正常通过 [应用商店](https://chrome.google.com/webstore/detail/troncuclass/oekepilgaknaenpkamkpiigfndkjlmil) 进行下载安装
+- Firefox 用户需在 [Releases](https://github.com/YanhuiJessica/TronCUClass/releases) 界面下选择合适的版本，点击对应版本附件中的 `xpi` 文件，将自动下载并提示安装，后续更新由浏览器完成
+
 ## Dev
 
 - 开发环境初始化