Update README.md

Added bundlephobia size image

Author: vivek12345

README.md

@@ -46,7 +46,7 @@ import React from 'react';
 />
 ```
 
-## 📦 Api
+## 📒 Api
 
 ### 🔔 react-polling
 
@@ -88,6 +88,10 @@ function onFailure(error) {
 }
 ```
 
+## 📦 Size
+
+<img src='./size.png' />
+
 ## 👍 Contribute
 
 Show your ❤️ and support by giving a ⭐. Any suggestions and pull request are welcome !