Update README.md

Author: duytq94

README.md

@@ -1,11 +1,11 @@
 # Chat Demo
 
-## Description:
+## Description
 * A chat app made by Flutter and Firebase.
 * Support login with google account, chat with any user, send text, image and sticker, update avatar and profile.
 * Watch the demo video for more clarity: https://youtu.be/MOHE68LI5Eg
 * Check my general guidance to know more and how to do it: https://medium.com/@duytq94/building-a-chat-app-with-flutter-and-firebase-from-scratch-9eaa7f41782e
 
-## Screenshot:
+## Screenshot
 
 <img src="https://raw.githubusercontent.com/duytq94/flutter-chat-demo/master/screenshots/FlutterChatDemo.gif" height="50%" width="50%">