adjust readme

README.md

@@ -2,7 +2,7 @@
 
 **The official iLert Go api bindings.**
 
-## In action
+## Create manual incident
 
 ```go
 package main
@@ -32,6 +32,32 @@ func main() {
 }
 ```
 
+## Ping heartbeat
+
+```go
+package main
+
+import (
+	"log"
+
+	"github.com/iLert/ilert-go"
+)
+
+func main() {
+	var apiKey = "heartbeat API Key"
+	client := ilert.NewClient()
+	result, err := client.PingHeartbeat(&ilert.PingHeartbeatInput{
+		APIKey: ilert.String(apiKey),
+		Method: ilert.String(ilert.HeartbeatMethods.HEAD),
+	})
+	if err != nil {
+		log.Println(result)
+		log.Fatalln("ERROR:", err)
+	}
+	log.Println("Heartbeat is ok!")
+}
+```
+
 ## Getting help
 
 We are happy to respond to [GitHub issues][issues] as well.