Generate podcast with 2 hosts using Convo Mode, with a user provided script

Starts a background job to produce an audio file with the provided script segments in convo mode. The response contains a job_id that can be used to query with the /podcast/{job_id} to query for status. Requires a valid X-API-TOKEN header.

**Note that generating via Convo Mode yields more natural results but takes longer.
Expect at least 1 minute of processing per minute duration of audio before investigating a potential failure.**


Throws:
- 429 if the user has too many jobs in flight.
- 400 if any voice_ids provided are invalid or if the length of voice_ids is not 2.