Added DockerHub badge

Using shields.io

Author: MasterGroosha

README.md

@@ -1,5 +1,6 @@
 # Bot to get users/chats IDs in Telegram
 
+<a href="https://hub.docker.com/r/groosha/my-id-bot"><img src="https://img.shields.io/badge/my--id--bot-docker%20hub-blue"></a>  
 Demo: [@my_id_bot in Telegram](https://t.me/my_id_bot).  
 
 This is a simple bot written with [aiogram](https://github.com/aiogram/aiogram) framework to show some IDs, like: