版本：
文件：
- https://cdn.bootcdn.net/ajax/libs/markdown-it-footnote/4.0.0/index.cjs.js
- https://cdn.bootcdn.net/ajax/libs/markdown-it-footnote/4.0.0/index.cjs.min.js
- https://cdn.bootcdn.net/ajax/libs/markdown-it-footnote/4.0.0/markdown-it-footnote.js
- https://cdn.bootcdn.net/ajax/libs/markdown-it-footnote/4.0.0/markdown-it-footnote.min.js