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 <andrew.wedgbury@realvnc.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>

man/weston.ini.man

@@ -79,6 +79,7 @@ The section headers are:
 .BR "keyboard       " "Keyboard layouts"
 .BR "terminal       " "Terminal application options"
 .BR "xwayland       " "XWayland options"
+.BR "screen-share   " "Screen sharing options"
 .fi
 .RE
 .PP
@@ -116,6 +117,7 @@ directory are:
 .nf
 .BR xwayland.so
 .BR cms-colord.so
+.BR screen-share.so
 .fi
 .RE
 .TP 7
@@ -457,6 +459,13 @@ The terminal shell (string). Sets the $TERM variable.
 sets the path to the xserver to run (string).
 .RE
 .RE
+.SH "SCREEN-SHARE SECTION"
+.TP 7
+.BI "command=" "/usr/bin/weston --backend=rdp-backend.so \
+--shell=fullscreen-shell.so --no-clients-resize"
+sets the command to start a fullscreen-shell server for screen sharing (string).
+.RE
+.RE
 .SH "SEE ALSO"
 .BR weston (1),
 .BR weston-launch (1),