Add an international landing page with info about the project: coronastatus.eu

[michaelmcmillan]

Original idea from Gavin.

Use coronastatus.eu to point to the other sites and have documentation on how to join community and get a website for your country.

[adriaandotcom]

That sounds great, was thinking of exactly this!

[adriaandotcom]

Maybe we should show the aggregated data of all countries as well.

[lseelenbinder]

I've started on this: #194.

[zacel]

Here is a pull request in reference to this issue: #560

It doesn't do this #188 (comment) yet because each countries data is siloed