Use Mermaind in Hugo

I think my solution here is not the best way to use Mermaid in Hugo. What is Mermaid? Mermaid is a sequence diagram generator written in Javascript. Not only sequence diagrams, Mermaid can also generate simple graphs. Enabling Mermaid in Hugo - use mermaid-cli Failures I tried two patterns but I failed both cases. Make a template in the theme Mainroad. I’ve Tried to copy MathJax template but failed. But this is the simplest and useful, so I need to study Hugo more.