feat(grafana alerts): setup a receiver for grafana alerts

otc/observability.t09.de/stacks/observability/victoria-k8s-stack/values.yaml

@@ -588,6 +588,18 @@ alertmanager:
     #       - namespace
 
     receivers:
+      - name: outlook
+        email_configs:
+          - smarthost: 'mail.mms-support.de:465'
+            auth_username: 'ipcei-cis-devfw@mms-support.de'
+            auth_password: 
+              name: email-user-credentials
+              key: connection-string
+            from: '"IPCEI CIS DevFW" <ipcei-cis-devfw@mms-support.de>'
+            to: 'franz.germann@telekom.de'
+            headers:
+              subject: 'Grafana Mail Alerts'
+            require_tls: true
       - name: blackhole
     # - name: "slack-monitoring"
     #   slack_configs: