When enabled via withResponsiveImages() or withResponsiveImagesIf() directly on the MediaCollection class, the responsive image generation doesn't respect the queue_conversions_by_default config. It always dispatches a job regardless of the config.

Is your feature request related to a problem? Please describe.
No, it's not related to a problem, but I think YAML is more suitable for configuration. It's easier to read than JSON.

Describe the solution you'd like
The approach is to change the default configuration file to YAML format. This should be backwards compatible, so by using a flag or by detecting JSON format we should trans