Submit a pull request with your final project idea and initial work plan (i.e. milestones).

This doesn’t have to be long (1-2 paragraphs and a list), but it should reflect lots of thought. The more work you do in the planning phase in terms of thinking through (and perhaps trying out) your ideas the easier the execution phase will be. If you’ve started your final, include a duplicate of your code (and keep working on the original).