default grub theme

if your grub is changed after update, run this in terminal

cd /tmp
wget https://github.com/Antergos/Cnchi/archive/master.zip
unzip master.zip
su
cp -R Cnchi-master/grub2-theme/Antergos-Default /boot/grub/themes
echo 'GRUB_THEME="/boot/grub/themes/Antergos-Default/theme.txt"' >> /etc/default/grubgrub-mkconfig -o /boot/grub/grub.cfg