edited readme

README.md

@@ -1,6 +1,7 @@
 # BMI Calculator [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-brightgreen.svg?style=flat-square)](http://makeapullrequest.com) <a href="https://github.com/Solido/awesome-flutter"><img alt="Awesome Flutter" src="https://img.shields.io/badge/Awesome-Flutter-blue.svg?longCache=true&style=flat-square" /></a>
 
 A Flutter App that calculates body mass index. 
+**It has 2 screens**
 
 Star⭐ the repo if you like what you see😉.
 [![Twitter Follow](https://img.shields.io/twitter/follow/Mikhael.svg?style=social)](https://twitter.com/mii_khael)