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>

manifests/wg-exporter-role-kube-prometheus.yaml

@@ -0,0 +1,56 @@
+apiVersion: rbac.authorization.k8s.io/v1
+kind: Role
+metadata:
+  labels:
+    app.kubernetes.io/component: prometheus
+    app.kubernetes.io/name: prometheus
+    app.kubernetes.io/part-of: kube-prometheus
+    app.kubernetes.io/version: 2.26.0
+  name: prometheus-k8s
+  namespace: kilo
+rules:
+- apiGroups:
+  - ""
+  resources:
+  - services
+  - endpoints
+  - pods
+  verbs:
+  - get
+  - list
+  - watch
+- apiGroups:
+  - extensions
+  resources:
+  - ingresses
+  verbs:
+  - get
+  - list
+  - watch
+- apiGroups:
+  - networking.k8s.io
+  resources:
+  - ingresses
+  verbs:
+  - get
+  - list
+  - watch
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: RoleBinding
+metadata:
+  labels:
+    app.kubernetes.io/component: prometheus
+    app.kubernetes.io/name: prometheus
+    app.kubernetes.io/part-of: kube-prometheus
+    app.kubernetes.io/version: 2.26.0
+  name: prometheus-k8s
+  namespace: kilo
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: Role
+  name: prometheus-k8s
+subjects:
+- kind: ServiceAccount
+  name: prometheus-k8s
+  namespace: monitoring