[Ubuntu-be] Group orders

[François Cauwe]

Hi everybody,

It seems that we missed a couple of group orders in the past, and I
would like to avoid that in the future. 
I made a wiki page for group orders, where evrybody can add his order,
such that it is easier to coordinate:
https://wiki.ubuntu.com/BelgianTeam/promotional-materials/Grouporder

I also added the poster action. So if you want some posters [1] but you
don't want 250 of them, please add your name. And you can arrange with
others to buy together a certain amount of them.

François