add warning about docker and mention nix/guix#157

SolalPirelli merged 2 commits into

sysartifacts:mastersysartifacts/sysartifacts.github.io:masterfrom

GuilloteauQ:156-docker_and_fpmsGuilloteauQ/sysartifacts.github.io:156-docker_and_fpmsCopy head branch name to clipboard