Auto line numbers in code blocks?

https://stackoverflow.com/questions/36122803/how-to-display-line-numbers-using-github-flavored-markdown-code

^ I already tried, ` '''json= ` did not work. Not sure if it would be worth the hassle, but just putting in the feature request in case it's easy or the markdown parser/library is already being replaced at some point for some other reason... a girl can dream!