Document the open template files button
docs(editor): split into intro + five sub-pages Refactors the 456-line Editor page into a short intro/overview linking to dedicated pages for Templates, Block Variants, Container Variants, Packaging, and Commands. Player-facing pages are menu-driven only; slash commands live exclusively on Editor-Commands. Packaging reflects the dtpacks/ package model (replaces the old imports/exports flow). Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>