OAS3.1: info.summary

[philsturgeon]

User story.

As an OpenAPI v3.1 users, I can see any OpenAPI v3.1 keywords that are editable in Studio, so I can have a consistent experience.

Is your feature request related to a problem?

OpenAPI v3.1 added info.summary and we're allowing users to edit this in Studio, so we'll need to start displaying it.

Describe the solution you'd like

In the API Component I should be able to see info.summary as a subtitle underneath info.title, probably on a smaller heading size and maybe lighter color.

It should be fairly short, most people will keep to a sentence or two not paragraphs. Spectral can push people to keep them short if they get abused.

Additional context

https://github.com/stoplightio/platform-internal/pull/5859

[mpodlasin]

https://github.com/stoplightio/elements/blob/main/packages/elements-core/src/components/Docs/HttpService/HttpService.tsx - should be added in this component