I'm not sure where to find the draft of the Fedora 22 Installation Guide, but I went through the Fedora 21 version steps in order to install the beta today. One suggestion for the new version of this page: http://docs.fedoraproject.org/en-US/Fedora/21/html/Installation_Guide/chap-booting-the-installation.html I recommend adding something like "On Mac hardware, hold down Option to enter the boot media selection menu." Mac hardware with Intel chips is rather common now, so I hope a significant number of people would be aided by that addition. I spent several hours trying to figure that out the first time I put Fedora on a Macbook. Thanks!
Thanks for the suggestion, Christopher. Added the note you suggested in https://da.gd/PZISf and it will be published in the F23 Installation Guide.
Released with the note included - you can see it here at the bottom of the page: https://docs.fedoraproject.org/en-US/Fedora/23/html/Installation_Guide/chap-booting-the-installation.html