docs: Showcase application UI in README with screenshots

Add README.md

docs: Add MIT License

UPD BookApplication.kt

Update BundleExtensions.kt

Update ToReadViewModel.kt

Update ToReadFragment.kt

Update StatsViewModel.kt

Update StatsFragment.kt

Update SortOptionsFragment.kt

Update ReadFragment.kt and ReadViewModel.kt

MainActivity.kt

FavoritesViewModel.kt

FavoritesFragment.kt

BookDetailViewModel.kt