howto add new language module

[alysonfs]

after receive the message "Could not find the language 'mermaid', did you forget to load/include a language module?", I did not find howto add new language module.

[cfbevan]

Looks like this project is using marked on the back end. Look at markserv-contrib-mod.markdown. The error is likely coming from marked directly. There are issues there talking about how to add mermaid as a language module.