Add rich output to Gradescope autograder

[taylorgibson]

Is your feature request related to a problem? Please describe.
Parsing autograder output is often difficult for students

Describe the solution you'd like
Implement a new Gradescope feature that allows for rich text output in autograder results: https://gradescope-autograders.readthedocs.io/en/latest/specs/#output-string-formatting

[chrispyles]

Can you give more context on what kind of rich content you'd like to see?

[taylorgibson]

I often hear from students that it's difficult to parse through the autograder standard text output. Since gradescope now allows for html or markdown output to be displayed, it's possible for the output to be organized in a way that summarizes the results in way that may be easier for students to understand. I've not yet dug into the details of what that could be or look like, but if this is something you're interested in trying to implement I could dig in a little bit more and report back.