The README said to set
ALT_CHAR = 27; like this FAQ said. Well, that didn't work. After some more google searching I found out how to do it!:
() = evalfile("emacs"); % Emacs-like bindings
Now it works like I think it should. I write it here because I'll probably forget for the next time.
Jed is the editor I use the most when not working in a graphical environment. Almost all of the code to this website has been developed using jed.