Prefer starting lorri with home-manager.
Note: I could have removed the `systemctl --user start lorri.service` line
before switching to home-manager by calling `systemctl --user enable
lorri.service`. This would have made a symlink in
`~/.config/systemd/user/default.target.wants`.
I didn't port everything from .ssh/config to home-manager. I omitted a few hosts
that I don't connect to anymore. I also omitted the `corp-ssh-helper`
configuration.