[APM] Docs for new machine learning integration

[formgeist]

Summary

The anomaly detection integration with Machine learning is changing to utilize a new job created specifically for detecting anomalies on environments by service and transaction type, making the integration much easier to enable and manage for the user as they will not have to create individual jobs per service and transaction type, but simply add it for their service environment.

Please ping Neha for review when a PR is ready.

Related

• [APM] Anomaly detection integration for all services/transaction.type per environment [Meta] #69479
• [APM] Anomaly detection: Add Anomaly detection view in Settings #70422
• [APM] Anomaly detection: Display Anomaly detection option in the APM header #70440

[elasticmachine]

Pinging @elastic/apm-ui (Team:apm)