[arch-releng] information for new users on booting the install media

[Ian Li]

I am very new to git and committing to a project in general, so apologies
about the deplorable formatting in both this email and the patch file's name

I don't think this really is an issue anywhere, but on the reddit ama
hosted today on r/linux I talked with Svenstaro about some information for
new users on booting up the install media, so that new users aren't
completely freaked out by the blank terminal.

I would review this to check that if this even works patch file and the
added lines, but I think it should work, considering it's just a few new
lines in .zlogin and I don't see why it shouldn't

thanks for your time looking over this, this is just a small change