docs(activity-logs): add PostHog AI query section

Documents the new activity_log kind in PostHog AI's read_data tool,
which allows users to query activity logs using natural language.

Ref: PostHog/posthog#47104

Author: inkeep[bot]

contents/docs/settings/activity-logs.mdx

@@ -193,6 +193,20 @@ This adds organization-level events to your activity feed, such as member invita
 
 You can view the change history for any individual resource. When viewing a feature flag, dashboard, experiment, or other resource, click the **History** tab to see all changes made to that specific item over time.
 
+## Query with PostHog AI
+
+[PostHog AI](/docs/posthog-ai) can answer questions about your activity logs using natural language. Ask questions like:
+
+- "Who changed the checkout-flow feature flag?"
+- "What experiments were modified last week?"
+- "Show me all dashboard changes by jane@example.com"
+
+PostHog AI can filter by scope (resource type), activity type, user, date range, and specific item IDs — the same filters available in the UI.
+
+To use this feature, open [PostHog AI](https://app.posthog.com/#panel=max) and ask your question. PostHog AI queries your activity logs and summarizes the results.
+
+> **Note:** Querying activity logs with PostHog AI requires the audit logs feature, which is available on Scale and Enterprise plans.
+
 ## Notifications
 
 You can subscribe to activity log changes and receive notifications via Slack, webhooks, or other destinations when specific events occur.