Automatic documentation of the cobra CLI

[fmartingr]

To avoid manually editing the documentation each time we modify the CLI, we can use the same approach hostctl uses to generate the CLI documentation.

Completion criteria

• Addition of a gen-cli-docs command in the Makefile that updates the docs/CLI.md with proper documentation of the CLI.
  • This command should accept a destination path (that defaults to docs/CLI.md) to use in the CI.
• A CI workflow that will run the command and compare it to the submitted docs/CLI.md to check if it is up to date, failing otherwise.