Update tidb-cloud/serverless-limitations.md

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: sunxiaoguang

tidb-cloud/serverless-limitations.md

@@ -20,7 +20,7 @@ We are constantly filling in the feature gaps between {{{ .starter }}}/Essential
 
 ### Connection
 
-- Database client connections that are held open longer than `30 minutes` may be terminated unexpectedly. We recommend starting with a 5 minutes maxiumm connection lifetime and increasing the connection lifetime if there is an impact on tail latency.
+- Database client connections that are held open longer than 30 minutes may be terminated unexpectedly. To avoid this, start with a 5-minute maximum connection lifetime and increase it if you observe a negative impact on tail latency.
 - Only [Public Endpoint](/tidb-cloud/connect-via-standard-connection-serverless.md) and [Private Endpoint](/tidb-cloud/set-up-private-endpoint-connections-serverless.md) can be used. You cannot use [VPC Peering](/tidb-cloud/set-up-vpc-peering-connections.md) to connect to {{{ .starter }}} or {{{ .essential }}} clusters. 
 - No [IP Access list](/tidb-cloud/configure-ip-access-list.md) support.