Docs: full Vantage 3D map setup guide; fully commented Paper example config

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DjMbLQujBHunCCu5GpsHaT

docs/live-map.md

@@ -1,5 +1,7 @@
 # Live Map (central Vantage)
 
+> **Setting it up?** Follow the step-by-step guide: [vantage-setup.md](vantage-setup.md). This page is the overview.
+
 The panel hosts a [Vantage](https://github.com/thoughts-on-things/vantage-mc) 3D map
 **for every game server**, so nobody has to run Vantage next to Minecraft.