Add LIBRARY_PATH environment variable for Docker to override config.json path

docker-compose.yml

@@ -14,6 +14,7 @@ services:
       - NODE_ENV=production
       - PORT=4000
       - DB_PATH=/app/data/audio_server.db
+      - LIBRARY_PATH=/data/music
     healthcheck:
       test: ["CMD", "wget", "--quiet", "--tries=1", "--spider", "http://localhost:4000/health"]
       interval: 30s