Add WireGuard monitor and docs

This commit adds a manifest for deploying a WireGuard prometheus
exporter, Role and RoleBinding for kube-prometheus to monitor the Kilo
namespace and a new guide in the docs about how to monitor Kilo.

Signed-off-by: leonnicolas <leonloechner@gmx.de>

website/docs/monitoring

@@ -0,0 +1,5 @@
+---
+id: monitoring
+title: Monitoring
+hide_title: true
+---

website/sidebars.js

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