The main Getting started with Qt has all the info and we should just
link to that.

Change-Id: I5cb5d3b3276989f06ad1fb7726d121928fbab22a
Reviewed-by: Paul Wicking <paul.wicking@qt.io>
Reviewed-by: Mats Honkamaa <mats.honkamaa@qt.io>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>