diagram support

[y-okumura-isp]

Hi, I really love knowledge. Thank you for awesome software!

I think hedgedoc (Formerly CodiMD), similar software to knowledge, supports special diagram syntax to write sequence diagram, flow chart, Graphviz, gannt chart and so on.
hedgedoc uses various libraries, including PlantUML, mermaid, abc.js.
https://hackmd.io/@codimd/extra-supported-syntax

Is there any plan to introduce such a syntax?

If so, I think it is good to start with mermaid. Because

• mermaid supports various diagrams: flow chart, sequence diagram, class diagram, gannt, and so on. see
• PlantUML is also good, but we need to introduce the PlantUML server and communicate with it from front-end JS

As I wrote the patch, I'll send PR right after.