Have a new Shift-Enter binding as an alias to the termial-level C-j (newline) or document it #42
Description
When iterating over an OCaml statement using the history, i often end up with a full line ended with ;;.
When this line gets a bit too complicated i then usually want to insert a newline somewhere in the middle, but if i type the Enter key it will instead just interpret it.
In web forums and instant messengers a common alternative to this kind of problem is to bind Shift-Enter to be "insert a new line where my cursor currently is instead of sending the message".
I'm not sure how that works but it seems that Ctrl-j is the key binding i'm looking for but it's somehow handled by the terminal and i find it rather hard to remember or even look for it in the first place.
To help with that i think it would be nice if Down.help () at least documented it (as terminal-level binding or something), and if possible it would be nice if down had Shift-Enter as it would feel quite natural for many users.