This ticket is a sub-task of https://phabricator.whonix.org/T21. This is for the design and implementation of an automatic backup mechanism for Onion Site keys.
*lsyncd configured like the example section "Inotify Backup - Backup Files When Changed" from http://backdrift.org/recursive-inotify-scripting-with-lsyncd.
*a systemd service that runs lsyncd command: lsyncd -pidfile /var/run/backup.lsyncd /etc/lsyncd.d/backup.lsyncd
The backup target will be the user home folder. The user makes a decision when and if the keys should go into the shared folder. For example they will want to do this when only the gateway is permitted access to the shared folder for security.