Great idea. I would hover make `--export` take only one argument, `[markdown, json, text]` (maybe have `md` and `txt` as aliases as well), which returns the result on stdout, and have an optional parameter `-o` specify an output path or file -- if it's an existing path, individual files will be exported, if it's a file (or doesn't exist yet), a single file will be written.

Go ahead and make the changes, if you push to your branch they'll be added to the pull request.