fix docker

Dockerfile

@@ -5,9 +5,7 @@ WORKDIR /app
 COPY requirements.txt .
 RUN pip install --no-cache-dir -r requirements.txt
 
-COPY . .
-
-# 配置文件不打包，由 volumes 挂载
-VOLUME ["/app/config.yaml", "/app/last_notifications.json"]
+COPY main.py notifier.py .
+COPY config.yaml.example config.yaml
 
 CMD ["python", "main.py"]