Groups of common rules

It would be useful to have a set predefined groups with well-known paths and related access rights. We can take some inspiration from [Pledge](https://justine.lol/pledge/#paths) and the [Filesystem Hierarchy Standard](https://refspecs.linuxfoundation.org/fhs.shtml).