Archive old IoT day websites

Created by: ChristieWittEclipse

We need to archive the old IoT day websites: https://iot.eclipse.org/eclipse-iot-day-santa-clara-2018/ https://iot.eclipse.org/eclipse-iot-day-santa-clara-2019/

We could also delete these old websites and then re-direct these old URLs to the new IoT day website: https://iot.eclipse.org/eclipse-iot-and-edge-day-san-jose-2020/

Let me know what you recommend.