Please add support for audio generation with multiple speakers

[FelipeLujan]

A screenshot that you have tested with "Try this API".

Please Allow customers using NodeJS client libraries to generate multi speaker audio generation like so https://cloud.google.com/text-to-speech/docs/create-dialogue-with-multispeakers

What would you like to see in the library?

No response

Describe alternatives you've considered

No response

Additional context/notes

thanks

[sofisl]

Please submit this to the API tracker itself (listed in the template) as these libraries are autogenerated. Thanks!