Sketch layout/UI design

[rugk]

streetcomplete/StreetComplete#1130 (comment):

Once, we've got this, maybe first add some sketch (via Inkscape?) so we have a common vision of how it should look like

Tools

• Put Inkscape file in repo here, I guess.
• For drafting, just use this issue?
• Or https://www.draw.io/? (But as far as I see, one also cannot collaborate there.)

What?

First finish #5 and #6. If we are sure about what it should look like, let's make a simple sketch on what should be placed where, how will we prioritize stuff, what should go right/left/top/bottom/etc.