That is not necessary.
Here are the first lines of
[root@beq-kaos ~]# cat /etc/default/grub
GRUB_DEFAULT=0
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo KaOS`
GRUB_CMDLINE_LINUX_DEFAULT="quiet showopts"
GRUB_CMDLINE_LINUX=""
The command
grub-mkconfig -o /boot/grub/grub.cfg
inserts the correct parameter automatically.
Greetings,
Bequimão