Hello! It took us a while, but it’s on-line now!
https://gnu.org/software/guix/blog/2018/a-packaging-tutorial-for-guix/ I took the liberty to add a paragraph about tarball authentication (it hadn’t occurred to me before), I hope that’s fine. Thanks a lot for your work and for your patience, Pierre! I’m sure it’ll be very useful to newcomers. Ludo’.