Start outbound Vapi calls from new Go High Level opportunities

## Requirements 
### Go High Level
- [Go High Level](https://www.gohighlevel.com/78476a2?fp_ref=1node) account
- Go High Level developer private app and credentials enabled in n8n
- Webhook URL (from n8n) added in your Go High Level private app

### Vapi
- A [Vapi](https://vapi.ai/?aff=onenode) account with credit
- A connected phone number which will make the calls
- An assistant created and ready to make calls
- Vapi api key 

### Useful links
- [GHL docs](https://developers.gohighlevel.com/)
- [Vapi docs](https://docs.vapi.ai/api-reference/calls/create)
- [n8n GHL credentials](https://docs.n8n.io/integrations/builtin/credentials/highlevel/)