Home-Manager got first level support for calendars and contacts.
Provided integrations are vdirsync and khal which I'm already using.
I therefore migrate from my own setup to the upstream setup.
Issue on home-manager project:
https://github.com/nix-community/home-manager/issues/2335
rclone is more flexible regarding storages.
nextcloud didn't play with keepass providing keyring.
rclone does not auto sync, I need to find a proper way to keep files in
sync without manuall calling commands …