docs: add network policies examples

This commit adds a guide for deploying Kubernetes NetworkPolicy support
to a cluster running Kilo.

Signed-off-by: Lucas Servén Marín <lserven@gmail.com>

website/docs/network-policies

@@ -0,0 +1,5 @@
+---
+id: network-policies
+title: Network Policies
+hide_title: true
+---

website/sidebars.js

@@ -7,7 +7,7 @@ module.exports = {
     {
       type: 'category',
       label: 'Guides',
-      items: ['topology', 'vpn', 'vpn-server', 'multi-cluster-services'],
+      items: ['topology', 'vpn', 'vpn-server', 'multi-cluster-services', 'network-policies'],
     },
     {
       type: 'category',