`openapiv3`: YAML Output

[aidandj]

🚀 Feature

Support YAML output for the generator.

Handled by the output_format option in v2

Please add a 👍 if this feature is useful/required for you.

[johanbrandhorst]

Could you elaborate on why this flag is desirable? It added quite a bit of complexity to the v2 generator, and to be honest, since the output is supposed to be consumed by other generators and not users directly, not to mention that JSON is actually valid YAML, I'm not sure we should add this flag without a lot of users asking for it, and with compelling reasons.

[aidandj]

I don't think I have a strong reason other than I prefer working in it. I think we should leave the issue open and collect some more input. Currently this would not be a blocker for me starting to use the v3 generator.