Merge pull request #5391 from wkruse/prometheus-annotations-doc

Add Prometheus annotations doc

docs/sources/reference/annotations.md

@@ -40,3 +40,10 @@ as the name for the fields that should be used for the annotation title, tags an
 For InfluxDB you need to enter a query like in the above screenshot. You need to have the ```where $timeFilter``` part.
 For InfluxDB you need to enter a query like in the above screenshot. You need to have the ```where $timeFilter``` part.
 If you only select one column you will not need to enter anything in the column mapping fields.
 If you only select one column you will not need to enter anything in the column mapping fields.
 
 
+## Prometheus Annotations
+![](/img/v3/annotations_prom.png)
+
+Prometheus supports two ways to query annotations.
+
+- A regular metric query
+- A Prometheus query for pending and firing alerts (for details see [Inspecting alerts during runtime](https://prometheus.io/docs/alerting/rules/#inspecting-alerts-during-runtime))