Improve layout, add images

android/gradle.properties

assets/images/blank.png

assets/images/left-foot.png

assets/images/left-hand.png

assets/images/right-foot.png

assets/images/right-hand.png

fastlane/metadata/android/en-US/changelogs/14.txt

fastlane/metadata/android/fr-FR/changelogs/14.txt

images/blank.svg

images/build_game_images.sh

images/left-foot.svg

images/left-hand.svg

images/right-foot.svg

images/right-hand.svg

lib/ui/widgets/game.dart

lib/ui/widgets/show_move.dart

pubspec.yaml