Chess.com Voice Commentary (simplified)

Previous voice commentary extensions for chess.com have broken for some reason. This is a simplified version that only reads new moves from 'board-layout-sidebar', so it is less likely to break in future, and easier to fix when it does. Source code at https://github.com/renshenw/chesscom-voice-simplified. "Piece Notation" in board settings must be "Text". Works for both human and computer opponents. All copyrights still go to chess.com.