Add steps on how to redeploy simple server.

[polina-c]

@parlough , thank you very mush for putting together simple server.

I forked it, clicked the button from my repo, went through wizard, and it magically worked out: https://simple-x2acmlikgq-uw.a.run.app

I added some images to 'public', that I want to serve, and now I do not know how to redeploy it.
Is there a command that I can run in project directory?