Update "coming soon" home page

Update temporary home page to say something like ... "lauching in 2022, check out ccss summer dev projects for more info" and link to the dev projects notion site.

<img width="1223" alt="Screenshot 2022-06-02 at 12 16 08 AM" src="https://user-images.githubusercontent.com/43223682/171551953-366ab189-cfcf-444b-9dd9-a5cc8a56f0f2.png">
