[Typo]: em dash spacing

Summary

Throughout the documentation, there's inconsistent use of the em dash (—, or —). Sometimes there's spaces surrounding them, and sometimes not.

Page

N/A

Details

Typically, em dashes are used without surrounding spaces. Personally, I prefer that style. However, I think whichever's fine as long as you follow a consistent style throughout.

I can open a PR making all these changes once I know which way we want to go: spaces or not.

该 issue 没有指定具体文件，因此首先检查文档中现有的破折号用法，并阅读链接的标点符号指南。确认项目要求使用空格还是不使用空格，然后统一更新文档中的所有出现位置，并验证不再存在空格混用的情况。