Include Gtk3 default settings from elementary os

[tintou]

The file settings.ini can be installed in either /usr/share/gtk-3.0/ or `/etc/gtk-3.0/

[cassidyjames]

@tintou is there a strong reason to use one path over the other?

[danirabbit]

etc would be more proper wouldn't it? Since share I think is supposed to more be resources the program needs to run and etc is supposed to be where system configuration is stored

[tintou]

No strong reason to use one or the other, share is used before etc if it does exists but they both work the same https://gitlab.gnome.org/GNOME/gtk/-/blob/gtk-3-24/gtk/gtksettings.c#L345