You use TaskPaper or a text editor. Doing isn't designed for full management, just a fast way to log.
^ (He's the author)
Hello.
Thanks for sharing! I also found the BBedit plugin, so that I can edit it from the TaskPaper link above. Here is a simple AppleScript to install it, when you don't have administrative rights on your user account:
do shell script "cd ~/Downloads/doing-master; gem install doing" with administrator privileges