Add Docker setup

README.md

@@ -76,6 +76,14 @@ bun run start
 
 The music player needs `ffmpeg` installed on the server.
 
+### Docker
+
+```bash
+docker compose up -d --build
+```
+
+The image builds the site with Bun and includes `ffmpeg`. It reads `.env` and serves on port 3000; set `HOST_PORT` to publish it on a different port.
+
 ## Configuration
 
 Copy `.env.example` to `.env` and fill in what you need. Every value is optional.