CLI - manifest command

[pileks]

Add a polywrap manifest command/set of commands within the CLI.

polywrap manifest schema

• should print out the schema for the polywrap manifest file
  • should print out the schema for the current version if a manifest file already exists in the working directory?
  • should print out latest schema if no manifest file exists?

polywrap manifest migrate

• should migrate the current manifest file to the latest version

Partly related to #202

[pileks]

• should print out the schema for the current version if a manifest file already exists in the working directory?

  • needs to support extensions as well
  • pass it a file, or have defaults

• should print out latest schema if no manifest file exists?

• print out in TS(w/ comments), YAML (w/ comments, default)

• print out (basically full) JSON Schema?

polywrap manifest schema - YAML
polywrap manifest schema --raw - full JSON

• polywrap manifest migrate
  • .polywrap/migrate folder with migration artifacts/old files? - Out of scope
  • confirm overwrite
    • -y option for auto-overwrite