Generate dockerfile

[kiootic]

• pageship generate dockerfile
• Write a Dockerfile, which FROM docker pull ghcr.io/oursky/pageship:$VERSION
  • The version should be equal to the version number of the running program
• User can build the docker image using docker build .
• Expect docker run -p xxxx:xxxx xxxx should be able to startup the server.
• Dockerfile should have a comment at the end of file; describe how to build & run it.

Test:

• Test Dockerfile generate correctly