Add minimal gameplay

android/gradle.properties

assets/icons/button_back.png

assets/icons/button_restart.png

assets/icons/button_start.png

assets/icons/difficulty_easy.png

assets/icons/difficulty_hard.png

assets/icons/difficulty_medium.png

assets/icons/empty.png

assets/skins/default_tile.png

assets/skins/default_tile_black.png

assets/skins/default_tile_empty.png

assets/skins/default_tile_white.png

fastlane/metadata/android/en-US/changelogs/2.txt

fastlane/metadata/android/en-US/changelogs/3.txt

fastlane/metadata/android/en-US/changelogs/4.txt

fastlane/metadata/android/en-US/changelogs/5.txt

fastlane/metadata/android/en-US/changelogs/6.txt

fastlane/metadata/android/fr-FR/changelogs/2.txt

fastlane/metadata/android/fr-FR/changelogs/3.txt

fastlane/metadata/android/fr-FR/changelogs/4.txt