Add runbook_url annotation for custom mixins

Signed-off-by: ArthurSens <arthursens2005@gmail.com>

manifests/kube-prometheus-prometheusRule.yaml

@@ -16,6 +16,7 @@ spec:
     - alert: TargetDown
       annotations:
         message: '{{ printf "%.4g" $value }}% of the {{ $labels.job }}/{{ $labels.service }} targets in {{ $labels.namespace }} namespace are down.'
+        runbook_url: https://github.com/prometheus-operator/kube-prometheus/wiki/targetdown
       expr: 100 * (count(up == 0) BY (job, namespace, service) / count(up) BY (job, namespace, service)) > 10
       for: 10m
       labels:
@@ -28,6 +29,7 @@ spec:
           and always fire against a receiver. There are integrations with various notification
           mechanisms that send a notification when this alert is not firing. For example the
           "DeadMansSnitch" integration in PagerDuty.
+        runbook_url: https://github.com/prometheus-operator/kube-prometheus/wiki/watchdog
       expr: vector(1)
       labels:
         severity: none
@@ -36,6 +38,7 @@ spec:
     - alert: NodeNetworkInterfaceFlapping
       annotations:
         message: Network interface "{{ $labels.device }}" changing it's up status often on node-exporter {{ $labels.namespace }}/{{ $labels.pod }}
+        runbook_url: https://github.com/prometheus-operator/kube-prometheus/wiki/nodenetworkinterfaceflapping
       expr: |
         changes(node_network_up{job="node-exporter",device!~"veth.+"}[2m]) > 2
       for: 2m