feat: XDG_USER_DIR based icons

[LykosEleutherios]

It's gonna be a good idea to get the pictures icon for both of them even thought if the first one starts with Capital letter or not... case there's a lot people who just like to use lowercase letters.

[cafkafk]

IMO these should follow XDG user directories https://wiki.archlinux.org/title/XDG_user_directories on linux, following XDG standards is nice, and that way we avoid taking responsibility for guessing what directories someone prefer to use for these things.