While it is easier to maintain the modules by prefixing them all with
`modules`, it is not easy when used from other flakes and/or modules.
This is my attempt on making it easier with appropriate namespaces.
Update home-manager user from the restructure
I think this is better for separating modules explicitly. This is also
considered as there are similar objects between modules (e.g., NixOS
and home-manager modules and users).
Revert users module to old position