Replace the use of marked with remark for doc/json generation #21476
Description
Summary: over time the node.js build process has outgrown marked and it's regular expression based processing model. See:
#21081 (comment)
#21081 (comment)
#21081 (comment)
It is time to replace it with something that involves a proper syntax tree which can be programmatically manipulated and from which artifacts like JSON can be confidently generated.