Convert install to systemd init

Remove the current launch script and use systemd init

Suggested systemd init script:

```
[Unit]
Description=Racecapture
After=basic.target

[Service]
Type=simple
User=pi
Restart=on-failure
ExecStart=/opt/racecapture/run_racecapture_rpi.sh -- -c graphics:show_cursor:0 -a -m cursor -c kivy:keyboard_mode:systemandmulti

[Install]
WantedBy=multi-user.target
```