I use a text to diagram tool called PlantUML. It’s perfect!
Now, I want to use it with my hugo site, through a short code. So, I I type a
code like below, I should see out like as the image.

A -> B : Hello
A <- B : Hi There!

Update: I spend many hourse trying to work this out. Created a firebase function to process posting and converting and yada yada. But finally gave up on Hugo. Until there is a plugin support in the core, this will be a very challenging thing.

During my (failed) research, I ran into Hexo and PlantUML filter plugin. I saw a a WordPress Migration plugin. I decided to give it a go.

In less than 20 minutes, I managed to install hexo, create a project, migrate wordpress items and got plantuml working.

I guess I will have to wait for hugo to mature a bit more. I really liked the speed and simplicity of hugo. But lack of plugin support in processing really killed it!