Enhance OpenAPI documentation with prefix and security info

[rgraff]

Added details about prefix and security scheme customization in OpenAPI spec.

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[zachdaniel]

I wonder if we should actually just fix that?

[zachdaniel]

Could you look into modifying the opts in the router? Something like this:

    opts =
      Keyword.put_new_lazy(opts, :prefix, fn ->
        conn.request_path
        |> Path.split()
        |> Enum.reverse()
        |> Enum.drop(Enum.count(conn.path_info))
        |> Enum.reverse()
        |> case do
          [] -> "/"
          paths -> Path.join(paths)
        end
      end)