README "How to run" now tells new users to press `S` → set Model Dir + HuggingFace token → Ctrl+S on first run (HF_HOME auto-derives), plus a "keeping current" note (git pull → re-run the install). Adds the missing `S` row to the keybindings table. Mirrors the c3 announcement (#459). Co-Authored-By: Claude Opus 4.8 <[email protected]> Claude-Session: https://claude.ai/code/session_01EfF565T9eSLaqGzidyJ1Pm