Clarify zoom levels

[jidanni]

In the PDF manual 'Figure 8: Maps Download Dialog: Example'
we see zoom levels 2 to 8. It turns out these can go all the way up to 1024.
But everybody knows that OSM maps go up to about zoom level 20. So obviously we are talking about something different.

[jidanni]

Indeed in the very same manual, section "17.1 Map Source", it is talking about the 1-20 zoom levels, not the 1-1024 zoom levels.

[jidanni]

OK, in the manual there is mention of 'Viking Zoom Level' and 'OSM Zoom Level', but no Rosetta Stone linking them together. Also e.g., in Figure 3 we see they go even to 32,000+. Anyway, every use of Zoom Level should have a prefix added so we know which kind you are talking about.