Seasons greetings

Closes #482 (closed)

@aspi.hzb @jandt-desy @konrad @frust45 here's a first draft for the text for the season greetings.

We wanted to send them by Friday, 15th, sorry it took me a bit longer to have a first draft.

Can you please have a look at the editorial?

👉 Review here

I kept it a bit vague on the achievements on purpose because it's not a newsletter, we just want to give people a general impression. But I probably missed something important.

For the vision part, it's just a proposal, I'm not so sure about it yet but thought it nice to use what people had expressed in Dresden to look a bit further than usual. Probably we need an extra sentence for the software cluster.