Fix FA version in readme

Author: michaelspiss

README.md

@@ -5,7 +5,7 @@
 [![Pub](https://img.shields.io/pub/v/font_awesome_flutter.svg)](https://pub.dartlang.org/packages/font_awesome_flutter)
 
 The *free* [Font Awesome](https://fontawesome.com/icons) Icon pack available 
-as set of Flutter Icons - based on font awesome version 6.5.1.
+as set of Flutter Icons - based on font awesome version 6.6.0.
 
 This icon pack includes only the *free* icons offered by Font Awesome out-of-the-box.
 If you have purchased the pro icons and want to enable support for them, please see the instructions below.