get supported languages, voices and models

Example response

{
  "tts": [
    {
      "name": "English (US)",
      "value": "en-US",
      "voices": [
        {
          "name": "Standard-A (Female)",
          "value": "ar-XA-Standard-A"
        }
      ]
    }
  ],
  "stt": [
    {
      "name": "Standard-A (Female)",
      "value": "ar-XA-Standard-A"
    }
  ],
  "ttsModel": [
    {
      "name": "Turbo v2",
      "value": "eleven_turbo_v2"
    }
  ]
}