The org mode would be fantastic. Even editing 'org' files with folding on '*' headings would be huge help. To be specific 1) recognize '.org' extension 2). fold on '*', '**', '***'... etc, same way as in markdown 3) support tabs indentation as in markdown. The rest of the features can be added later, but this basic org-mode support will bring a number of fans.
Thank you for a great editor! For now, I will just convert from org to md, and back.