VScroll and HScroll should mention the effect they have on UpDown objects

**Page on which the enhancement should be made**
https://docs.dyalog.com/20.0/object-reference/properties/vscroll/
https://docs.dyalog.com/20.0/object-reference/properties/hscroll/

**Describe the enhancement you would like**
VScroll ¯1 makes an updown arrows vertical
HScroll ¯1 makes an updown arrows horizontal

**Additional information**
reported by a customer.
