What client & kbfs releases are the official binaries built from?

[sersorrel]

Title – e.g. are the official releases built from the git tags on keybase/client and keybase/kbfs?

Reason being that I want to use Keybase on my ARM Chromebook, but there aren't any official binaries for ARM, and per #2938 it doesn't look likely that there ever will be; I'd like to avoid the situation described in the client README:

some of the things in this repo are explorations, and the app you build from source just might not do what it says it's doing.