Catch-up release documentation - @YulNaumenko

[mikecote]

Go over previous PRs that have been merged since Alerting GA to document anything that requires it.

List of PRs created by @YulNaumenko requiring docs:
https://github.com/elastic/kibana/pulls?q=is%3Apr+label%3A%22Team%3AAlerting+Services%22+label%3Aneeds_docs+is%3Aclosed+author%3AYulNaumenko

• [EventLog] Added event log API to get events for multiple saved objects. [EventLog] Added event log API to get events for multiple saved objects. #87596 Docs PR: [Event Log] Extended README.md with the documentation for a REST API and Start plugin contract. #92562
• License checks for alerts plugin License checks for alerts plugin #85649 Docs PR: [Alerts][Docs] Extended README.md and the user docs with the licensing information. #92564
• Added default dedupKey value as an {{alertInstanceId}} to provide grouping functionality for PagerDuty incidents. Added default dedupKey value as an {{alertInstanceId}} to provide grouping functionality for PagerDuty incidents. #84598 Docs PR: [Actions][Doc] Added user doc for default value for PagerDuty deduplication key. #92746
• [Alerting UI] Added ability to assign alert actions to resolved action group in UI [Alerting UI] Added ability to assign alert actions to resolved action group in UI #83139. Already added to the user docs: https://www.elastic.co/guide/en/kibana/master/defining-alerts.html
• Used SO for saving the API key IDs that should be deleted Used SO for saving the API key IDs that should be deleted #82211 Docs PR: [Alerts][Doc] Added README documentation for API key invalidation configuration options. #92757
• Implemented Alerting health status pusher by using task manager and status pooler for Kibana status plugins 'kibanahost/api/status' Implemented Alerting health status pusher by using task manager and status pooler for Kibana status plugins 'kibanahost/api/status' #79056 Docs PR: [Alerts][Doc] Added README documentation for alerts plugin status and framework health checks configuration options. #92761

[elasticmachine]

Pinging @elastic/kibana-alerting-services (Team:Alerting Services)

[YulNaumenko]

Closing on behalf of creation all missing docs PRS