update docs for input:scroll_factor (#506)

* update docs for input:scroll_factor

* back out this change

pages/Configuring/Variables.md

@@ -177,6 +177,7 @@ _[More about Animations](../Animations)._
 | scroll_method | Sets the scroll method. Can be one of `2fg` (2 fingers), `edge`, `on_button_down`, `no_scroll`. [libinput#scrolling](https://wayland.freedesktop.org/libinput/doc/latest/scrolling.html) [2fg/edge/on_button_down/no_scroll] | str | \[\[Empty\]\]
 | scroll_button | Sets the scroll button. Has to be an int, cannot be a string. Check `wev` if you have any doubts regarding the ID. 0 means default. | int | 0 |
 | scroll_button_lock | If the scroll button lock is enabled, the button does not need to be held down. Pressing and releasing the button once enables the button lock, the button is now considered logically held down. Pressing and releasing the button a second time logically releases the button. While the button is logically held down, motion events are converted to scroll events. | bool | 0 |
+| scroll_factor | Multiplier added to scroll movement for external mice. Note that there is a separate setting for [touchpad scroll_factor](#touchpad).  | float | 1.0 |
 | natural_scroll | Inverts scrolling direction. When enabled, scrolling moves content directly instead of manipulating a scrollbar. | bool | false |
 | follow_mouse | Specify if and how cursor movement should affect window focus. See the note below. [0/1/2/3] | int | 1 |
 | mouse_refocus | If disabled and `follow_mouse=1` then mouse focus will not switch to the hovered window unless the mouse crosses a window boundary. | bool | true |