Is your feature request related to a problem? Please describe. / 你的需求是否与某个问题相关？
EN: When reading long documents, the Table of Contents (TOC) is essential for navigation. However, it often occupies significant screen space or requires manual clicks to toggle. Currently, I cannot find a way to quickly toggle the TOC using the keyboard, which can interrupt the reading flow for power users.
ZH: 在阅读长篇文档时，目录（TOC）对导航至关重要。然而，它有时会占用过多的屏幕空间，或者需要频繁手动点击来切换显隐。目前我没有找到通过键盘快速切换目录的方法，这对于习惯使用快捷键的用户来说，阅读体验不够连贯。
Describe the solution you'd like / 描述你希望的解决方案
EN: I suggest adding a keyboard shortcut feature to toggle the TOC. More importantly, this feature should be fully configurable via the configuration file, as I haven't found any existing options for this.
ZH: 我建议增加一个通过键盘快捷键切换目录显隐的功能。更重要的是，这个功能应该完全可以在配置文件中自定义，因为目前我还没有发现相关的配置项。
Is your feature request related to a problem? Please describe. / 你的需求是否与某个问题相关？
Describe the solution you'd like / 描述你希望的解决方案