screen-share: Add screen-share command to weston.ini man page
screen-share: Add screen-share command to weston.ini man page

This adds a description of the screen-share command configuration key to the
weston.ini man page.

[Pekka Paalanen: removed the sentence about default value, because the
default value is empty, and AFAIU cannot work.]

Signed-off-by: Andrew Wedgbury <4c086aa64f8d10ff07d56c92496b4e9d24903d72@realvnc.com>
Reviewed-by: Pekka Paalanen <0f6ae7001e34c37b02fb2c1c2573ddf8f442136a@collabora.co.uk>

udoprog/weston,mchalupa/weston,jonnylamb/weston,sir-murray/weston,mchalupa/weston,eyolfson/weston,krezovic/weston,xorgy/weston,Tarnyko/weston-xdg_surface_present,xorgy/weston,krezovic/weston,giucam/weston,jonnylamb/weston,Tarnyko/weston-xdg_surface_present,kwm81/weston,Gnurou/weston,giucam/weston,sir-murray/weston,Fantu/compositor-spice,Gnurou/weston,eyolfson/weston,kwm81/weston,Fantu/compositor-spice,Fantu/compositor-spice,udoprog/weston