A minimalist distribution of Linux

Sounds interesting, especially if it allows to use docker hub as a package manager. I'm a bit confused about persistence. It is mentioned on github that you can have a "persistent state" mounting a volume, but later it is said that system changes will be swept anyway (in "console is ephemeral"). I assume the "persistent state" is just about `/home` and `/opt` ? Also, does this mean someone can't edit an etc file once and for all ?