fix description

app.py

@@ -143,7 +143,7 @@ Pose image generated by this tool has pose data in the image itself. You can reu
 - "alt + drag" to **move**
 - "shift + drag" to **rotate** (move right first, release shift, then up or down)
 - "space + drag" to **range-move**
-- "[", "]" or mouse "Alt + wheel" to shrink or expand **range**
+- "[", "]" or "Alt + wheel" or "Space + wheel" to shrink or expand **range**
 - "ctrl + Z", "shift + ctrl + Z" to **undo**, **redo**
 - "ctrl + E" **add** new person
 - "D + click" to **delete** person