Swiping from -> to tests, new readme, and ndkVersion bump

[NorseGaud]

Added test for mobile-dev-inc/Maestro#2117

Updated ndkVersion:

❯ flutter build apk
Your project is configured with Android NDK 26.1.10909125, but the following plugin(s) depend on a different Android NDK version:
- integration_test requires Android NDK 26.3.11579264
Fix this issue by using the highest Android NDK version (they are backward compatible).
Add the following to /Users/norsegaud/demo_app/android/app/build.gradle.kts:

    android {
        ndkVersion = "26.3.11579264"
        ...
    }
Font asset "MaterialIcons-Regular.otf" was tree-shaken, reducing it from 1645184 to 1472 bytes (99.9% reduction). Tree-shaking can be disabled by providing the --no-tree-shake-icons flag when building your app.
e: The daemon has terminated unexpectedly on startup attempt #1 with error code: 0. The daemon process output:
    1. Kotlin compile daemon is ready
warning: [options] source value 8 is obsolete and will be removed in a future release
warning: [options] target value 8 is obsolete and will be removed in a future release
warning: [options] To suppress warnings about obsolete options, use -Xlint:-options.
3 warnings
Running Gradle task 'assembleRelease'...                          136.3s
✓ Built build/app/outputs/flutter-apk/app-release.apk (21.1MB)

Updated Readme with things you need to know/do to run the app and tests.