Add designer-centric recruitment task

Part of https://github.com/cargomedia/fuboo-bizdev/issues/293

> I think we could give them a task to actually redesign part of our website since this is a core skill required (plus we get some ideas/input from different people) - so we can judge on the things they will actually be doing. We can give them a screenshot of a page with generic content, give some guidance on what should be done and let them do what they do best.