Arnaud Hatzenbuhler

For the repo I cannot say. For the PR, I need to fix some things, but the main feature is present. Hopefully, I will take a look this week ;)

Nor the different `default--packages` used to install packages ;) I could handle both ways (1 package per line and TOML), but honestly, if this PR is merged, it would be...

@smorimoto For you review ;)