Merge branch 'feature/null-safety' of https://github.com/funwithflutter/mastering_animation_course into feature/null-safety

Author: Gordon Hayes

section_2/built_in_explicit_animations/README.md

@@ -1,16 +1,7 @@
-# transition_widgets_example
+# Transition Widgets
 
-A new Flutter project.
+Initialize build folders:
 
-## Getting Started
-
-This project is a starting point for a Flutter application.
-
-A few resources to get you started if this is your first Flutter project:
-
-- [Lab: Write your first Flutter app](https://flutter.dev/docs/get-started/codelab)
-- [Cookbook: Useful Flutter samples](https://flutter.dev/docs/cookbook)
-
-For help getting started with Flutter, view our
-[online documentation](https://flutter.dev/docs), which offers tutorials,
-samples, guidance on mobile development, and a full API reference.
+```dart
+flutter create .
+```