The markdown editor mentions that
All common programming languages are supported, but you can add more using the customized download here. Save the file and overwrite pagedown/highlight.min.js.
However, when I go to the mentioned webpage, after selecting the languages I need, I get a zip file not a single file and even if one extract it there is no file named highlight.mini.js. Is the instructions outdated?
This issue on GitHub also complains about the same thing but there is no answer from developer.