~/.config/sway: Map terminal to mod+shift+return like in dwm

Maybe I have this habit from even earlier, possibly even from XMonad.

.config/sway/config

@@ -74,7 +74,7 @@ input type:touchpad events disabled
# Basics:
#
    # Start a terminal
    bindsym $mod+Return exec $term
    bindsym $mod+Shift+Return exec $term
    # Kill focused window
    bindsym $mod+Shift+c kill