Introduce argument for passing in API URL for the slack-bot only model (--api-url or -a) - this can be set via REGINALD_API_URL environment variable too)
note: Leaving this as draft until a new version from llama-index to integrate this change - at time of writing, has been merged but no version bump with this change)
--api-urlor-a) - this can be set viaREGINALD_API_URLenvironment variable too)