Use Markdown as another default file format

[Korodny]

I'd rather not introduce another file format into my workflow, or constantly mess with importing/exporting files.

I do realize using an alien file format means I can't use Document Sets or store settings within documents - but in return I get something that integrates itself into my existing workflow seamlessly.

[nateProjects]

I'd love to have this option too. Even if it had to be manually configured somehow.