Building, upstream tracking and YTSage's own README moved to the wiki; README
points there.
The history is not rewritten, unlike every other repository here. This one
still merges from oop7/YTSage and a rewrite would change every commit id, which
costs more than a clean history is worth in a fork. .github/ and
readme-translations/ are upstream's files and stay where upstream put them.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
