[fedora-arm] Initial Chromebook install instructions

[Jon Masters]

https://fedoraproject.org/wiki/Architectures/ARM/Samsung_Chromebook_2012

Do not follow any of these instructions unless:

1). You know what you are doing.
2). You understand that you may cause damage to your Chrombook. In
particular, you may permanently damage the audio (speaker) hardware
until we have UCM working properly in ALSA. This is at your risk.

PLEASE do not remove the giant obnoxiously offensive warning from that
wiki page that I intentionally added to scare people off in the interim.

Jon.