I've also added the ability to use
``` class preformatted code that will be displayed verbatim with tabs converted to 4 spaces ```The
class is optional, and must consist of alphanumeric characters followed by a newline. The main code follows between the ``` delimiters. It will retain the line breaks and spacing from the PGML source code, and no further PGML commands are performed on the code (so you can't do bold or math or anything like that).
I haven't included any code highlighting javascript myself, but you can do so as you have been doing. Making that part of PGML will require adding the javascript to the WeBWorK distribution and so it will be something I can't easily add locally for this course.
This is not very heavily tested, so let me know if you see anything fishy. I hope this meets your needs.