Update Dockerfile

Dockerfile

@@ -20,6 +20,7 @@ RUN wget https://github.com/gitpod-io/openvscode-server/releases/download/openvs
 
 # 设置工作目录
 WORKDIR /app
+RUN mkdir -p /app/downloaded_videos && chmod 777 /app/downloaded_videos
 
 # 将当前目录下的所有文件复制到容器中
 COPY . /app