Separate commands for lint, bundle, decorate

Is your feature request related to a problem? Please describe.

As a user, I know which operations I want to perform, and in what order.

• I want to lint intentionally, not as a side effect of a bundle command
• I want to decorate either before or after linting
• By having the commands as a separate step, I can easily report (for example in CI) which part failed.

Describe the solution you'd like

Additional command redocly decorate and no additional operations (linting, decorating) as side-effects of other operations such as bundle.

We might also need a pre-processor command since that's another step that gets done by bundle.

Describe alternatives you've considered

Multiple config blocks for the same API with different names so that I can run one step and then another for each stage of the process to work around this limitation and try to restrict commands to a single operation at a time.

Start by tracing the existing bundle command and the linting, decorating, and pre-processing steps it currently performs. Done means lint and decorate are independently invocable through Redocly CLI, bundle has no such side effects, and the need for a separate pre-processor command is resolved.