Added example alerting config

README.md

@@ -77,6 +77,7 @@ http://localhost:9090/metrics
 - [Documentation index](docs/README.md)
 - [Configuration reference](docs/configuration.md)
 - [Metrics reference](docs/metrics.md)
+- [Prometheus alerting rules](docs/alerting.md)
 - [Operations and troubleshooting](docs/operations.md)
 - [Architecture and adding collectors](docs/architecture.md)
 
@@ -93,6 +94,12 @@ Metrics are collected in the background according to `proxmox.interval`.
 Prometheus scrapes the most recently collected values and does not trigger a new
 request to Proxmox VE.
 
+An example alert group for node, guest, storage, subscription, disk, ZFS, SDN,
+and capacity conditions is available in
+[`examples/pve-exporter.rules.yml`](examples/pve-exporter.rules.yml). See the
+[alerting guide](docs/alerting.md) for the `rule_files` configuration and
+collector requirements.
+
 ## Docker
 
 Pull the latest published image from the Gitea container registry: