Codebase Out of Date

Hello Andrea,

First of all thank you so much for all of your efforts in putting together phenomenal educational resources for Flutter! I've been working through your _Get Started With Flutter_ course and it has been very educational as part of purchasing your _Pro_ course.

I noticed that many of your other repos you have updated to be functional and usable that you have associated with your instructions in the course. However, this particular repo I noticed hasn't been touched since 2019 and doesn't comply with null safety among other issues with outdated packages. If you are able to make the time to update this Git repo to be functional with the current release of Dart and Flutter I would greatly appreciate it!

Thank you for your time,
-James Ewing

Start by running the repository with the current Dart and Flutter releases and reviewing its outdated package dependencies. Update the project for null safety and current packages; done means the example is functional with the current Dart and Flutter versions.

Written by the indexing model from the issue text.