Allow the rich text editor to be disabled

Because not all of us work with rich text, or variants thereof, Sudowrite immediately becomes less useful if the editor is rich text only. There's no plaintext export option, either. I work in plaintext with markdown, and cut-and-pasting from rich text creates problems. Until recently, the composition window allowed plaintext cut and pasting, but that's been replaced by the annoying rich text-only offering. Please allow the rich text editor to be disabled. For those of us who don't want or need it. Thanks.