docs: Correct variable names in FAQ documentation (#3694)

docs: Use plural variable names in FAQ security group examples

docs/faq.md

@@ -23,13 +23,13 @@ By default, EKS creates a cluster primary security group that is created outside
 ```hcl
   create_node_security_group = false # default is true
 
-  eks_managed_node_group = {
+  eks_managed_node_groups = {
     example = {
       attach_cluster_primary_security_group = true # default is false
     }
   }
   # Or for self-managed
-  self_managed_node_group = {
+  self_managed_node_groups = {
     example = {
       attach_cluster_primary_security_group = true # default is false
     }
@@ -39,13 +39,13 @@ By default, EKS creates a cluster primary security group that is created outside
 2. By not attaching the cluster primary security group. The cluster primary security group has quite broad access and the module has instead provided a security group with the minimum amount of access to launch an empty EKS cluster successfully and users are encouraged to open up access when necessary to support their workload.
 
 ```hcl
-  eks_managed_node_group = {
+  eks_managed_node_groups = {
     example = {
       attach_cluster_primary_security_group = true # default is false
     }
   }
   # Or for self-managed
-  self_managed_node_group = {
+  self_managed_node_groups = {
     example = {
       attach_cluster_primary_security_group = true # default is false
     }