Configure Download button to switch between JSON and YAML format

[sarahwspoon]

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

This blog post (https://redocly.com/blog/hide-download-button/) on the Redocly website implies that the OpenAPI definition source file can be downloaded in either YAML or JSON format, however, it appears to default to JSON format with no obvious way to change it.

Describe the solution you'd like

A configuration setting to set this to either YAML or JSON format would be greatly appreciated!