Support OpenAPI 3.1 nullable syntax

[m0uka]

Since OpenAPI 3.1, the 'nullable' field was removed in favor of type arrays.
Gitbook does not support this functionality, and shows no type details at all.

The example below shows the field as being either null or an array, but does not show the definitions of the item.

payout_splits:
  type:
    - 'null'
    - array
  items:
    $ref: '#/components/schemas/ProductPayoutSplitDto'
  description: "The payout splits for revenue distribution.\nRequires special approval."

[nolannbiron]

Hi @m0uka

Thanks for flagging this. We’ll take a look and keep you posted.