docs: Move examples that are more like test cases to the new tests/ directory; add better example configurations (#3069)

* chore: Move examples that are more like test cases to the new `tests/` directory

* chore: Stash

* feat: Add better examples for EKS managed node groups

* chore: Add better examples for self-managed node groups

* chore: Update docs and correct `nodegroup` to `node group`

examples/eks-managed-node-group/eks-al2023.tf

@@ -0,0 +1,52 @@
+module "eks_al2023" {
+  source  = "terraform-aws-modules/eks/aws"
+  version = "~> 20.0"
+
+  cluster_name    = "${local.name}-al2023"
+  cluster_version = "1.30"
+
+  # EKS Addons
+  cluster_addons = {
+    coredns                = {}
+    eks-pod-identity-agent = {}
+    kube-proxy             = {}
+    vpc-cni                = {}
+  }
+
+  vpc_id     = module.vpc.vpc_id
+  subnet_ids = module.vpc.private_subnets
+
+  eks_managed_node_groups = {
+    example = {
+      # Starting on 1.30, AL2023 is the default AMI type for EKS managed node groups
+      instance_types = ["m6i.large"]
+
+      min_size = 2
+      max_size = 5
+      # This value is ignored after the initial creation
+      # https://github.com/bryantbiggs/eks-desired-size-hack
+      desired_size = 2
+
+      # This is not required - demonstrates how to pass additional configuration to nodeadm
+      # Ref https://awslabs.github.io/amazon-eks-ami/nodeadm/doc/api/
+      cloudinit_pre_nodeadm = [
+        {
+          content_type = "application/node.eks.aws"
+          content      = <<-EOT
+            ---
+            apiVersion: node.eks.aws/v1alpha1
+            kind: NodeConfig
+            spec:
+              kubelet:
+                config:
+                  shutdownGracePeriod: 30s
+                  featureGates:
+                    DisableKubeletCloudCredentialProviders: true
+          EOT
+        }
+      ]
+    }
+  }
+
+  tags = local.tags
+}