Sort the scripts and scenes into folders

main/ holds the main window and top bar, quiz/ the quiz and its parts,
player/ the music player, popups/ every popup and what they share, data/ the
songs, players, playlist and settings, server/ the MusicServer client,
common/ the list row and GameLog, and themes/ the themes and style boxes.

main/top_bar.gd

@@ -0,0 +1,22 @@
+class_name TopBar
+extends Control
+## The bar along the top of the main window, with the title and the buttons for things
+## that are not part of a quiz.
+
+signal search_pressed
+signal sync_pressed
+signal statistics_pressed
+signal shortcuts_pressed
+signal about_pressed
+signal qr_pressed
+
+@onready var sync_button: Button = $SyncButton
+
+
+func _ready() -> void:
+	$SearchButton.pressed.connect(search_pressed.emit)
+	sync_button.pressed.connect(sync_pressed.emit)
+	$StatisticsButton.pressed.connect(statistics_pressed.emit)
+	$ShortcutsButton.pressed.connect(shortcuts_pressed.emit)
+	$AboutButton.pressed.connect(about_pressed.emit)
+	$QRButton.pressed.connect(qr_pressed.emit)