implemented scene_manager

.godot/editor/create_recent.Node

.godot/editor/editor_layout.cfg

.godot/editor/filesystem_cache8

.godot/editor/filesystem_update4

.../game.tscn-editstate-c2a7af834e91ff64325daddf58e45dc0.cfg

.godot/editor/project_metadata.cfg

.godot/editor/recent_dirs

.godot/editor/script_editor_cache.cfg

.godot/global_script_class_cache.cfg

.godot/uid_cache.bin

main.tscn

scenes/board.tscn

scenes/scene_manager.tscn

scenes/title_screen.tscn

scripts/board.gd

scripts/scene_manager.gd

scripts/title_screen/title_screen.gd