The article stated that they linked to a specially modified version of Ubuntu to be able to load it on the Chromebook. Standard Mint won't load.
Edit: Also there isn't a version of Mint at present to run on an ARM processor.
LMDE Mate 64-bit, LM17.3 Cinnamon 64-bit
Debian Mate 64-bit, Xubuntu xenial 64-bit, Ubuntu-Mate 14.04 64-bit, Antergos Xfce 64-bit, PCLinuxOS Mate 64-bit