how to use hexo-filter-mermaid-diagrams or is there any other ways to use mermaid?

[RonaldLN]

我尝试使用hexo-filter-mermaid-diagrams，按照README.md中的步骤进行配置，但在Step 3这里，我没有在 /node_modules/hexo-theme-aurora/layout 中找到 after_footer 文件，
尝试在 index.ejs 中添加 README.md 中的代码但运行时报错了，我应该怎么办？

I'm trying to use hexo-filter-mermaid-diagrams, following the steps in README.md, but at Step 3, I don't find the after_footer file in /node_modules/hexo-theme-aurora/layout, and when I try to add the code from README.md to index.ejs, it gives an error when running. What should I do?