This is /etc/defaults/rc.conf but for individual services. Unlike
/etc/rc.conf.d, files in /etc/defaults/rc.conf.d are shipped by the
operating system and shouldn't be modified by users, so they should
not have the @config tag.

This allows optional packages to install their own default config
instead of dumping everything in /etc/defaults/rc.conf.

While here, move rc.d and rc.conf.d to the rc package.