Support concise outline and symbol list

[yarray]

What should we improve?

Currently when navigating a long specification we have to rely on the YAML outline which is not quite convenient. Without semantics of openapi the outline is arbitrarily deep and hard to navigate. As a consequence, typing @ to search symbol brings too many results which are not useful. The following picture shows the condition:

How should we improve it?

It would be better to provide a seperate outline panel and help navigate paths and schemas. Also it would be useful if @ will bring paths and schemas only.

Why should we improve it?

OpenAPI docs are quite verbose and navigation is painful. This feature will greatly improve the experience.

Describe alternatives you've considered

Currently I manually collapse the YAML outline every time.

Additional context

[tatomyr]

Thank you for the idea. We will consider implementing it in the future.