Replay note 30 days retention on free plan (#10324)

Author: jas-kas

docs/product/session-replay/replay-details.mdx

@@ -50,7 +50,7 @@ Find a complete list of built-in fields and custom tags associated with a replay
 
 ## Retention
 
-Replays are retained for 90 days in sentry.io (the same retention period as other event types, such as Errors and Transactions). The retention period is not configurable.
+Replays are retained for 90 days in sentry.io for paid plans (the same retention period as other event types, such as Errors and Transactions). For free plans, replays are retained for 30 days in sentry.io. The retention period is not configurable.
 
 ## Inbound Filtering