Add missing newlines before printing the Dockerfile content

[terrytangyuan]

Before:

Dockerfile created successfully in /tmp/tmp.qyMdb0vI8X/DockerfileFROM python:3.10-slim
WORKDIR /app

RUN apt-get update && apt-get install -y        iputils-ping net-tools iproute2 dnsutils telnet        curl wget telnet        procps psmisc lsof        traceroute        bubblewrap        && rm -rf /var/lib/apt/lists/*

After:

Dockerfile created successfully in /tmp/tmp.qyMdb0vI8X/Dockerfile

FROM python:3.10-slim
WORKDIR /app

RUN apt-get update && apt-get install -y        iputils-ping net-tools iproute2 dnsutils telnet        curl wget telnet        procps psmisc lsof        traceroute        bubblewrap        && rm -rf /var/lib/apt/lists/*