Added Nuget icon.

README.md

@@ -2,7 +2,7 @@
 
 The package provides a tool to send data to Zabbix in the same way as [zabbix_sender](https://www.zabbix.com/documentation/4.0/ru/manual/concepts/sender) tool. It implements [Zabbix Sender Protocol 4.0](https://www.zabbix.org/wiki/Docs/protocols/zabbix_sender/4.0).
 
-# Installation
+# Installation [![NuGet](https://img.shields.io/nuget/v/ZabbixSender.Async.svg)](https://www.nuget.org/packages/ZabbixSender.Async)
 
 NuGet package is available [here](https://www.nuget.org/packages/ZabbixSender.Async/).