Documented floating_scroll

sway/sway.5.txt

@@ -156,6 +156,18 @@ or triggered at runtime.
 	enabled, left click is used for resizing and right click for dragging. The
 	mode paramenter is optional and defaults to _normal_ if it isn't defined.
 
+**floating_scroll** behavior <gaps_inner|gaps_outer|custom>::
+	If set to _gaps_inner_, adjusts inner gaps of the windows on scrolling
+	while holding the floating modifier. If set to _gaps_outer_, adjusts
+	outer gaps. If set to _custom_, performs user-defined commands,
+	specified in *floating_scroll up|down*.
+
+**floating_scroll** <up|down> [command]::
+	Sets the command to be executed on scrolling up and down
+	(respectively) while holding the floating modifier, when
+	*floating_scroll behavior* is set to _custom_. Resets the command,
+	when given none.
+
 **focus_follows_mouse** <yes|no>::
 	If set to _yes_, the currently focused view will change as you move your
 	mouse around the screen to the view that ends up underneath your mouse.