Update README.md

Author: bergusman

README.md

@@ -1,2 +1,26 @@
 # APNs Provider
+
 HTTP/2 Apple Push Notification service (APNs) provider for Go with token-based connection
+
+Example:
+
+```Go
+key, err := apns.AuthKeyFromFile("AuthKey_XXXXXXXXXX.p8")
+if err != nil {
+	log.Fatal(err)
+}
+
+token := apns.NewToken(key, "XXXXXXXXXX", "XXXXXXXXXX")
+client := apns.NewClient(token, nil)
+
+n := &apns.Notification{
+	DeviceToken: "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
+	Host:        apns.HostDevelopment,
+	Topic:       "com.example.app",
+	Payload: apns.BuildPayload(&apns.APS{
+		Alert: "Hi",
+	}, nil),
+}
+
+fmt.Println(client.Push(n))
+```