Function: refill-mode

Toggle automatic refilling (Refill mode).
With a prefix argument ARG, enable Refill mode if ARG is
positive, and disable it otherwise. If called from Lisp, enable
the mode if ARG is omitted or nil.

Refill mode is a buffer-local minor mode. When enabled, the
current paragraph is refilled as you edit. Self-inserting
characters only cause refilling if they would cause

For true "word wrap" behavior, use `visual-line-mode' instead. (fn &optional ARG)