Redraw the design flow pictures in the documentation

Now the pictures of the flow look like this:

But we are missing the Qt Design Studio workflow. And how the QDS can be used for live preview for the QSR also (the safe QML objects are treated like normal QML objects in the live preview that can be done in the host or in the target)

One might also consider the bare metal options to be shown, and co-location with Qt for MCU as well.