[LyX/master] Arabic UserGuide.lyx: update from Hatim

[Uwe Stöhr]

commit e8678bc6060fd88c74bac15eda22118f96264c6f
Author: Uwe Stöhr <uwesto...@lyx.org>
Date:   Tue Mar 20 03:32:13 2018 +0100

    Arabic UserGuide.lyx: update from Hatim

 lib/doc/ar/UserGuide.lyx | 3845 ++++++++++++----------------------------------
 1 files changed, 1004 insertions(+), 2841 deletions(-)