fix: Update link for course

README.md

@@ -1,6 +1,6 @@
 # Stacked [![Pub Version](https://img.shields.io/pub/v/stacked)](https://pub.dev/packages/stacked)
 
-[![Flutter Web Mastery Release Banner](https://github.com/Stacked-Org/stacked/blob/master/assets/banner.jpeg)](https://dane-mackier-s-school.teachable.com/p/master-flutter-on-the-web?utm_medium=banner&utm_campaign=stacked_readme)
+[![Flutter Web Mastery Release Banner](https://github.com/Stacked-Org/stacked/blob/master/assets/banner.jpeg)](https://masterflutterweb.carrd.co?utm_medium=banner&utm_campaign=stacked_readme)
 
 ## [Checkout out the new and improved Docs](https://stacked.filledstacks.com/)