I've participated in several game jams as part of a team.  We've submitted the software under one of the other developers, so even though I have participated in an entry, it looks like I didn't submit one.  Wouldn't care much, but I'm doing this for my resume.  Are we missing something?  Is there a way to tie a submission to more than one developer?

Not yet, but it's an oft-requested feature.

Multi-developer submissions are done by adding all developers as “admins” to the project page. One person will create and submit the page, and everyone else will be added as an admin. Every contributor will be displayed on the submission page, and it will also give everyone the “Submitted” flag on their community posts and comments.