[UPDATE] Install FreeBSD on Linode

[nmelehan]

From DOCS-149, clarification was asked for in step 4. Original comments from customer:

I am confused by step 4:

4. Boot into Rescue Mode with the installer disk mounted to /dev/sda and access your Linode using Lish via SSH from the Remote Access tab of the Linode Manager.

Which of the profiles created in step 3 should be selected when clicking the boot button during step 4? Oh right, it's very ambitious in the tutorial because the previous
step is all about configuring disks and since there is a boot button
in the part of the UI where step 3 was done, I didn't think that
rescue corresponded to a separate menu item (because that wasn't
specified).

The proposed change is to link to the Booting into Rescue Mode section of the Rescue and Rebuild guide in step 4. This section provides detailed instructions for how to boot into Rescue Mode for those unfamiliar with this feature.