docs(openapi): Add docs to throw different exceptions under the same …

[AxelDavid45]

…http code

PR Checklist

Please check if your PR fulfills the following requirements:

• [ x] The commit message follows our guidelines: https://github.com/nestjs/docs.nestjs.com/blob/master/CONTRIBUTING.md

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Docs
• Other... Please describe:

What is the current behavior?

Issue Number: N/A

What is the new behavior?

I think it's worthy to add this part to the docs because the decorator @ApiExtraModels() doesn't have an concrete example of its implementation.

Does this PR introduce a breaking change?

• Yes
• No

Other information

[micalevisk]

can you add a hint at the end to tell from where refs is imported? I didn't find any reference to this utility in the docs yet

Like this one

[AxelDavid45]

@micalevisk Done, is it OK?

[micalevisk]

@Injectable()
export class CatController {
  @ApiExtraModels(BadAppCodeException, BadEmailException)
  @ApiBadRequestResponse({
    schema: {
      oneOf: refs(BadAppCodeException, BadEmailException),
    },
  })
  multipleErrorsResponse() { ... }
}

some indentation

[AxelDavid45]

@micalevisk Added indentation