Creating a new page for the TheiaCon 2022 event

Hi, we would like to launch a simple save-the-date page for TheiaCon 2022 event. This page will follow the 2021 style, with only the top banner updated.

https://events.eclipse.org/2021/theiacon/

You can find the needed assets here:

TheiaCon_2022_assets.zip

Thanks!

CC @serina