Zachary Muranaka

* Changes the example app's use of `WillPopScope`, which has been deprecated since [flutter!132249](https://github.com/flutter/flutter/pull/132249), to instead use `PopScope` * A few other minor things like making widgets const where recommended...

Closes #13 by addressing the relevant issues

There is no analysis_options.yaml included in the project. Just by including this in the project with the default recommended Flutter lints we can see the following issues: * `PinchZoom` constructor...