feature: Support "well known" user directories

[B3QL]

I haven't found a package that provides that functionality and I think that it might be a good use case to handle it here.
All major OSes have some form of default user directories like:

$HOME/Desktop
$HOME/Documents
$HOME/Downloads
$HOME/Music
$HOME/Pictures
$HOME/Public
$HOME/Videos

The paths may also differ based on system language preferences, so the i18n needs to be handed as well.

https://wiki.archlinux.org/title/XDG_user_directories
https://support.apple.com/guide/mac-help/folders-that-come-with-your-mac-mchlp1143/mac

[B3QL]

@zoofood what do you think about it?