Add steps on how to redeploy simple server.

@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?

Start by reading the simple server's existing deployment instructions and checking how files added to public are served. Document the project-directory command or steps needed to redeploy after those files change, with completion shown by a fresh deployment serving the added images.

Written by the indexing model from the issue text.