turn `make specsplit` into a task which only runs when the converter and/or source files have changed, i.e. only regenerate the good/bad reference files for testing when there's any potential change pending.
turn `make specsplit` into a task which only runs when the converter and/or source files have changed, i.e. only regenerate the good/bad reference files for testing when there's any potential change pending.

GerHobbelt/markdown-it,GerHobbelt/markdown-it