conf: add example for AreaBottomEdge on clickpad buttons
conf: add example for AreaBottomEdge on clickpad buttons

Those that use clickpad buttons as buttons can see cursor jumps as the press
on the touchpad - largely caused by the finger changing shape as the
pressure changes and thus moving the hotspot.

Simple fix is to define the clickpad soft button areas as dead areas, but
this cannot be set as general option as it would break for those that use
tapping.

Signed-off-by: Peter Hutterer <b9c50af7afa7642f6f854434cda9ffe54ece8b85@who-t.net>
(cherry picked from commit 2159b5d26207c83efea6efca7fa5765df95a4219)

RsrchBoy/xserver-xorg-input-synaptics,RsrchBoy/xserver-xorg-input-synaptics