Support #17320

Updated by Peter Amstutz 12 months ago

* The document should explain that the single node install is not a production install, but can be converted into one, and should include links on how to:
** Switching to your own hostname and configuring certificates (providing your own or using Lets Encrypt)
** Change the authentication provider
** Switch to using an S3 bucket for keepstore backend (maybe including migrating blocks from a local keep directory into s3)
** Stop crunch-dispatch-local and set up arvados-dispatch-cloud