通过Alt+B（Mac为Control+B）开关的通用仿生阅读脚本，只作用于英文内容，优先处理字典中的词，并根据单词长度进行加粗
These are all versions of this script. Show only the versions where the code changed.
```27e5f6e skip `
` elements https://github.com/yitong2333/Bionic-Reading/pull/1/commits/27e5f6e02ed287671600559a86da3fb4a952fd43 ```
修复了句首的空字符串处理的小问题感谢@Lin-Guanguo找出了Bug
加入判断用户系统的功能，根据系统自适应快捷键Windows为alt+b，Mac为control+b
