feat(kanvas): add Kubernetes Services tutorial

Migrate the Exploring Kubernetes Services with Meshery tutorial to
content/en/kanvas/tutorials/kubernetes/kubernetes-services.md.

- Add hands-on tutorial covering ClusterIP, NodePort, and LoadBalancer
  service types using Meshery Playground and Kanvas
- Preserve legacy URL aliases (/guides/tutorials/kubernetes-services,
  /kanvas/tutorials/kubernetes-services)
- Use ## / ### heading hierarchy matching existing Kanvas tutorials
- Add descriptive alt text on every screenshot for accessibility
- Link screenshots to existing assets on docs.meshery.io
- Add intro content to kubernetes/_index.md

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Signed-off-by: Yi Nuo <218099172+yi-nuo426@users.noreply.github.com>

Author: yi-nuo426

content/en/kanvas/tutorials/kubernetes/_index.md

@@ -1,3 +1,11 @@
 ---
-title: Kubernetes 
----
+title: Kubernetes
+description: Hands-on Kubernetes tutorials using Meshery Playground and Kanvas.
+weight: 9
+categories: [Tutorials]
+---
+
+Work through hands-on Kubernetes scenarios in
+[Meshery Playground](https://playground.meshery.io/) — an interactive live
+cluster environment — using Kanvas to design, deploy, and explore core
+Kubernetes resources without writing YAML.