[aur-general] archinstall script suggestion

[Jude DaShiell via aur-general]

In the case where /dev/sda is selected for installation and an installer
chooses to format the whole disk and install a basic partition system on
the disk and any other data is already on the disk archinstall errors out.
In this case, wipefs -a /dev/sda run first clears the pre-existing data
and partition structure and archinstall then operates correctly.