Implement collapsable navigation menus like Wikipedia on moblie

The Python documentation table of contents is massive. It's unwieldy on a mobile device. A lot of that comes from itemising all the changelogs going back to 3.0 release. In and of itself, that's fine, but it takes a lot of scrolling to find anything. The indentation also isn't terribly clear to identify what is a subheading of what. Highly nested headings exacerbates this.

Collapsable TOC headings, used on sites like Wikipedia, would help tremendously with this. That way, mobile users could see a cleaner layout resembling the desktop TOC display, then be able to drill down into whatever topic they're looking for.

首先检查主题的目录标记和移动导航样式，然后将当前的嵌套布局与 Wikipedia 的可折叠导航进行比较。确定标题在移动设备上应如何展开和折叠，包括 changelog 部分，并在移动尺寸的文档构建中验证结果。