Ask HN: Platform to crowdsource writing a novel or short story

Hi,

Are there platforms available that let you crowdsource writing a novel or a short story. Where you start writing something, people read and make suggestions on what comes next. Or they correct if you make some technical mistakes in your writing or anything else.

I read somewhere that 'The Martian' author took suggestions from online readers while writing the book and it helped him with the technical stuff etc.