Add a custom label to blackbox metrics and update instructions

stack_orchestrator/data/stacks/monitoring/monitoring-watchers.md

@@ -44,9 +44,13 @@ Add the following scrape configs to prometheus config file (`monitoring-watchers
   - job_name: 'blackbox'
     ...
     static_configs:
-      - targets:
-        - <AZIMUTH_GATEWAY_GQL_ENDPOINT>
-        - <LACONICD_GQL_ENDPOINT>
+      - targets: [<AZIMUTH_GATEWAY_GQL_ENDPOINT>]
+        labels:
+          # Add destination label for pre-configured alerts
+          destination: 'azimuth_gateway'
+      - targets: [<LACONICD_GQL_ENDPOINT>]
+        labels:
+          destination: 'laconicd_gql'
   ...
   - job_name: laconicd
     ...
@@ -120,10 +124,12 @@ Add scrape config as done above for any additional watcher to add it to the Watc
 
 ### Grafana alerts config
 
-Place the pre-configured watcher alerts rules in Grafana provisioning directory:
+Place the pre-configured watcher and blackbox endpoint alerts rules in Grafana provisioning directory:
 
   ```bash
   cp monitoring-watchers-deployment/config/monitoring/watcher-alert-rules.yml monitoring-watchers-deployment/config/monitoring/grafana/provisioning/alerting/
+
+  cp monitoring-watchers-deployment/config/monitoring/blackbox-alert-rules.yml monitoring-watchers-deployment/config/monitoring/grafana/provisioning/alerting/
   ```
 
 Update the alerting contact points config (`monitoring-watchers-deployment/config/monitoring/grafana/provisioning/alerting/contactpoints.yml`) with desired contact points
@@ -136,7 +142,7 @@ Add corresponding routes to the notification policies config (`monitoring-watche
       - receiver: SlackNotifier
       object_matchers:
         # Add matchers below
-        - ['grafana_folder', '=', 'WatcherAlerts']
+        - ['grafana_folder', '=~', 'WatcherAlerts|BlackboxAlerts']
   ```
 
 ### Env