My argument isn't that the README won't be easily readable between git interfaces. My argument is mostly a) I expect that conversion rates will be higher going from GH -> GL if the guide is hosted on GH, and b) the guide is already hosted on GH, so, therefore c) you'll need a much better reason than a specious argument about dogfooding to compel a change.

I mean, it's just a git directory with a README.md--it's not like it can't be both places, but the argument from dogfooding I don't think is a good one.