docs: update InstanceIdNodeName doc to recommend access entries (#2392)

* chore: update InstanceIdNodeName doc to recommend access entries

* Update nodeadm/doc/examples.md

Co-authored-by: Nick Baker <ndbaker1@outlook.com>

* Update nodeadm/doc/examples.md

Co-authored-by: Carter <cartermckinnon@gmail.com>

---------

Co-authored-by: Nick Baker <ndbaker1@outlook.com>
Co-authored-by: Carter <cartermckinnon@gmail.com>

Author: 3 people

nodeadm/doc/examples.md

@@ -73,14 +73,15 @@ There are several benefits of doing this:
 ### To enable this feature, you will need to:
 1. [Create a new worker node IAM role](https://docs.aws.amazon.com/eks/latest/userguide/create-node-role.html#create-worker-node-role)
     - ⚠️ **Note**: you should create a new role when migrating an existing cluster to avoid authentication failures on existing nodes.
-2. [Update the `aws-auth` ConfigMap with above created role](https://docs.aws.amazon.com/eks/latest/userguide/auth-configmap.html#aws-auth-users). For example:
+2. Configure authorization for the role using username `system:node:{{SessionName}}`, for example by [creating an access entry](https://docs.aws.amazon.com/eks/latest/userguide/creating-access-entries.html) of type `EC2` for the new role:
+    -  ⚠️ **Note**: you can still use the [legacy `aws-auth` ConfigMap](https://docs.aws.amazon.com/eks/latest/userguide/auth-configmap.html#aws-auth-users) to grant access, but services like [EKS Managed Node Groups](https://docs.aws.amazon.com/eks/latest/userguide/managed-node-groups.html) will require the use of access entries.
 ```
-- groups:
-  - system:bootstrappers
-  - system:nodes
-  rolearn: $ROLE_CREATED_ABOVE
-  username: system:node:{{SessionName}}
+aws eks create-access-entry \
+  --cluster-name $CLUSTER_NAME \
+  --principal-arn $ROLE_CREATED_ABOVE \
+  --type EC2
 ```
+
 3. Enable the feature gate in your user data:
 ```
 ---