Versioning OpenAPI specs page

[ZanSara]

In #235 we added a Swagger component to document in great detail the REST API. However, I realized that this documentation will work only for master, as the file it's not versioned.

In https://github.com/deepset-ai/haystack/pull/2228 I introduce versioning of openapi.json on Haystack's side. However, I am not sure how we can manage such versions on the documentation side.

Is there a way for a Component to know which version of the docs are being loaded? If yes, then modifying Swagger.tsx to read the correct file should be possible: https://github.com/deepset-ai/haystack-website/blob/37303b09eac7b6261ed6ee45e33d320ea323d0d8/components/Swagger.tsx#L11