Update README.md

Author: bluebill1049

README.md

@@ -6,6 +6,8 @@
     </p>
 </div>
 
+<img src="https://react-hook-form.com/static/dev-tool-4a61171024c1e1985abfac2bebc7dbee.png" />
+
 <p align="center">Performant, flexible and extensible forms with easy to use validation.</p>
 
 <div align="center">