add documentation for session persistence

Author: salonichf5

content/ngf/overview/gateway-api-compatibility.md

@@ -176,7 +176,7 @@ See the [controller]({{< ref "/ngf/reference/cli-help.md#controller">}}) command
     - `name`: Not supported.
     - `timeouts`: Not supported.
     - `retry`: Not supported.
-    - `sessionPersistence`: Not supported.
+    - `sessionPersistence`: Supported.
 - `status`
   - `parents`
     - `parentRef`: Supported.
@@ -226,7 +226,7 @@ See the [controller]({{< ref "/ngf/reference/cli-help.md#controller">}}) command
       - `extensionRef`: Supported for SnippetsFilters.
     - `backendRefs`: Partially supported. Backend ref `filters` are not supported.
     - `name`: Not supported.
-    - `sessionPersistence`: Not supported.
+    - `sessionPersistence`: Supported.
 - `status`
   - `parents`
     - `parentRef`: Supported.

content/ngf/overview/nginx-plus.md

@@ -13,4 +13,6 @@ NGINX Gateway Fabric can use NGINX Open Source or NGINX Plus as its data plane.
 - **Robust metrics**: A plethora of [additional Prometheus metrics]({{< ref "/ngf/monitoring/prometheus.md" >}}) are available.
 - **Live activity monitoring**: The [NGINX Plus dashboard]({{< ref "/ngf/monitoring/dashboard.md" >}}) shows real-time metrics and information about your server infrastructure.
 - **Dynamic upstream configuration**: NGINX Plus can dynamically reconfigure upstream servers when applications in Kubernetes scale up and down, preventing the need for an NGINX reload.
+- **Session persistence**: NGINX Plus provides support for cookie-based session persistence, allowing client requests to be consistently routed to the same upstream pod.
+- **Load balancing methods**: NGINX Plus provides advanced, latency-aware load balancing methods (such as `least_time` and `least_time last_byte inflight`) that route traffic based on time to first byte or full response, optionally factoring in in-flight requests for smarter upstream selection.
 - **Support**: With an NGINX Plus license, you can take advantage of full [support](https://my.f5.com/manage/s/article/K000140156/) from NGINX, Inc.