[FR] Support for downloading OpenAPI specification file

[sserrata]

Is your feature request related to a problem?

Today, there is no method for downloading the source OpenAPI specification file, for use "offline", e.g. Postman, Insomnia, SDK generation, some other doc tool, etc.

Describe the solution you'd like

Ability to download a formatted, enriched copy of the OpenAPI spec for each set of API docs.

Describe alternatives you've considered

Linking to GitHub?

Additional context

Single spec and multi should be "easy" since we can potentially just read them in, convert to postman collection, then back to OAS yaml file. Micro-specs could be a challenge since each spec is a part of the whole.