You are looking for project ideas? I've made this huge-ass shell script for a asciidoctor package format (to make projects with media portabel). Then came the thought, i should redo this in python and then "while i'm on it, why not a universal lightweight markup package format?". But i don't have the time, so if you're up for it...
And the thing i don't have the time because, it's complicated. Maybe in a few months.