Adding second text input field to Interactive Content update page in Moodle

Hi there, 

I was wondering if someone could provide a couple of first steps or tutorial link for how one might go about adding another text field (like a second Description field) to the H5P content type creation page in Moodle. The desired result is to have the contents of that field output after or below the actual interactive H5P object: just a place to put some HTML. 

My first guess is that it would require extending the mod_hvp_mod_form class in mod_form.php?

Thanks and best, 

matt