Add k3s cluster expansion documentation and scripts

- Complete expansion guide for 2/4/6 node scenarios
- Quick join scripts for worker and master nodes
- Health check and diagnostic scripts
- Quick reference card for common operations

k3s/my-blog/04-redis.yaml

@@ -0,0 +1,40 @@
+# 04-redis.yaml - Redis for WordPress session storage
+apiVersion: v1
+kind: Service
+metadata:
+  name: redis-service
+  namespace: demo-space
+spec:
+  ports:
+  - port: 6379
+    targetPort: 6379
+  selector:
+    app: redis
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: redis
+  namespace: demo-space
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: redis
+  template:
+    metadata:
+      labels:
+        app: redis
+    spec:
+      containers:
+      - name: redis
+        image: redis:7-alpine
+        ports:
+        - containerPort: 6379
+        resources:
+          requests:
+            memory: "64Mi"
+            cpu: "100m"
+          limits:
+            memory: "128Mi"
+            cpu: "200m"