Here's a question that does that, though it's only a quick proof of concept. You will undoubtedly wish to improve on the feedback. An xml export is attached. If you import that and look under Advanced Customisation you'll see that the template language is set to Python but the Ace language (which is what the student sees in the answer box) is HTML. The Python template code just parses the HTML and prints the tags and attributes found.
And after a correct submission:
