New cool tool: md-to-mm! You can think of it as a preprocessor for markdown, turning it into mm macros so groff can read it. From there, groff can turn it into (most importantly) PDFs, but also things like HTML, but you can find dozens of MD -> HTML converters on Github.
For some reason going from markdown to a pdf is hard to to - but not anymore! You can take a look at the project’s readme to see what syntax is supported.
The program reads from stdin and outputs on stdout, very suckless.
cat file.md | md-to-mm | groff -mm -tbl -Tpdf > out.pdf