Revise MVK documentation: replace mermaid diagrams with images, add new sections for single node and three node viability, and enhance the usage slide with additional context.

pages/three-node-happy.md

@@ -0,0 +1,36 @@
+---
+level: 2
+---
+
+# MVK for pre-production
+
+### MVK, three node, production
+
+<div class="grid grid-cols-1">
+
+<div class="flex justify-center">
+    <img src="/k8s-3.drawio.png" alt="3-node Kubernetes diagram">
+</div>
+
+</div>
+
+
+<!--
+
+why is MVK 'viable' ?
+
+Out of the box K8s examples and some deployments are not useable without other externalities
+
+* Persistent storage - often built in to managed kubernetes cloud platforms
+* Ingress - is also provided by cloud providers, K8s does not natively have this
+* ETCD is often offered as the 'management plane', again as part of managed kubernetes by cloud providers
+
+K3s does not use k8s traditional 3 node ETCD unless you configure it to do so
+
+MKK's infctl pipelines configure 3 node k3s on all 3 nodes
+
+it also adds Longhorn for persistent storage
+
+ingress is impossible without metallb and some kind of load balancer - traefik being my preference but others could be used, of course
+
+-->