Update the `system-info` directory with the addition of a `systemd`
service file and an new Linux script to display current CPU temperature
and core/thread utilization. Update `.conduit.yaml` with addition
`apt` dependencies `sysstat` and `jq`. Update the install and remove
scripts to setup and tear down the `systemd` user unit. Lastly, decrease
the `tmux` status line update interval from 5 to 2 seconds.
The `system-info` directory contains scripts and configuration files to
install and remove a `launchd` user agent on macOS which collects
information about the system and outputs it to the file
`~/.cache/tmux/system-info`. This file is then read periodically by
`tmux` and the contents displayed in the status line.
