[Docs]: Update Docs for `grafana_machine_learning_alert`

[SeamusGrafana]

Update the Docs for grafana_machine_learning_alert to clarify usage.

• Specify that one of job_id or outlier_id is required
• Specify that anomaly_condition can only be used with job_id
• Specify the acceptable values for anomaly_condition one of any, high, low and what each does.
• Specify the acceptable values for no_data_state one of Alerting, NoData or OK
• Correct Import Example to show Format: Import ID must be in the format '/(jobs|outliers)/<jobID>/alerts/<alertID>'
• Correct outlier_id (String) The forecast this alert belongs to. to outlier_id (String) The outlier this alert belongs to.