Is your feature request related to a problem? Please describe.
There are Python libraries that provide MD conversion. I am though not sure how good GTK is at displaying maths. If it is possible, without much tinkering with GTK, could you point me to the location in the code where MD parsing is handled, so I could work on a solution myself potentially as well and open a PR. If some GTK issues need a workaround, I can sadly not help all that much, as my experience with GTK is fairly limited.

Describe the solution you'd like
Parse the output of say Mathstral to actual mathematical formulas.

Describe alternatives you've considered
Another option imo would also be to add a button that says something like "view as LaTeX PDF" and then uses some conversion algorithm to convert the normal output to LaTeX. I could work on that, but the PDF reader-part is something I don't know how to do. Well apart from opening it in an external reader