revert doc changes for unreleased functionality

Author: piyush-tiwari

GettingStarted.md

@@ -36,8 +36,6 @@ The native ingress controller itself is lightweight process and pushes all the r
     + [Web Firewall Integration](#web-firewall-integration)
     + [Ingress Level HTTP(S) Listener Ports](#ingress-level-https-listener-ports)
     + [TCP Listener Support](#tcp-listener-support)
-    + [Network Security Groups Support](#network-security-groups-support)
-    + [Load Balancer Preservation on `IngressClass` delete](#load-balancer-preservation-on-ingressclass-delete)
   * [Dependency management](#dependency-management)
     + [How to introduce new modules or upgrade existing ones?](#how-to-introduce-new-modules-or-upgrade-existing-ones)
   * [Known Issues](#known-issues)
@@ -606,39 +604,6 @@ spec:
                   number: 8081
 ```
 
-### Network Security Groups Support
-Users can use the `IngressClass` resource annotation `oci-native-ingress.oraclecloud.com/network-security-group-ids` to supply
-a comma separated list of Network Security Group OCIDs.
-The supplied NSGs will be associated with the LB associated with the `IngressClass`.
-
-Example:
-```yaml
-apiVersion: networking.k8s.io/v1
-kind: IngressClass
-metadata:
- annotations:
-   oci-native-ingress.oraclecloud.com/network-security-group-ids: ocid1.networksecuritygroup.oc1.abc,ocid1.networksecuritygroup.oc1.xyz
-```
-
-### Load Balancer Preservation on `IngressClass` delete
-If you want the Load Balancer associated with an `IngressClass` resource to be preserved after `IngressClass` is deleted,
-set the annotation `oci-native-ingress.oraclecloud.com/delete-protection-enabled` annotation to `"true"`.
-This annotation defaults to `"false"` when not specified or empty.
-
-OCI Native Ingress Controller will aim to leave the LB in a 'blank' state - clear all NSG associated with the LB,
-delete the Web App Firewall associated with the LB if any, and delete the `default_ingress` BackendSet when the `IngressClass` is deleted with this annotation set to true.
-Please note that users should first delete all `Ingress` resources associated with this `IngressClass` first, or orphaned resources like Listeners, BackendSets, etc. will
-still be present on the LB after the `IngressClass` is deleted
-
-Example:
-```yaml
-apiVersion: networking.k8s.io/v1
-kind: IngressClass
-metadata:
- annotations:
-   oci-native-ingress.oraclecloud.com/delete-protection-enabled: "true"
-```
-
 ### Dependency management
 Module [vendoring](https://go.dev/ref/mod#vendoring) is used to manage 3d-party modules in the project.
 `vendor/` folder contains all 3d-party modules.