OpenAPI: response 200 for /generate is wrong

[fmvilas]

Describe the bug

It says a 200 response is application/json: https://github.com/asyncapi/server-api/blob/master/openapi.yaml#L41

Expected behavior

It should instead be:

application/octet-stream:
  schema:
    type: string
    format: binary

[github-actions]

Welcome to AsyncAPI. Thanks a lot for reporting your first issue. Please check out our contributors guide and the instructions about a basic recommended setup useful for opening a pull request.
Keep in mind there are also other channels you can use to interact with AsyncAPI community. For more details check out this issue.