Add mission statement at the top

[bitboxer]

We should add a small explanation at the top of the page that explains what Ruby Berlin e.V. is and what it does. And we need to explain that the "Berlin" part of the name is there because of history.

[bascht]

@bitboxer I finally got around and just hijacked the DNS, so now we can finally push some changes. Would you still like to contribute to the mission statement? Me and @sareg0 are happy to join in 😸

[bitboxer]

Yes, totally. Let's talk!

[bascht]

@bitboxer SERIOUSLY? A 60 SECOND RESPONSE TIME TO A THREE YEAR OLD ISSUE? BODO, DO YOU EVER SLEEP? 😆

[bitboxer]

You got really lucky. I just came home after a 3 hour dinner with friends 😆