Initial commit

Half-baked state. Most of the UI is mostly done, but the integration
with Grist (or any other data provider) is still missing.

cart_list.gd

@@ -0,0 +1,18 @@
+extends VBoxContainer
+
+const list_entry_scene = preload("res://cart_list_entry.tscn")
+
+func _ready() -> void:
+	Global.cart_updated.connect(_on_cart_updated)
+	_on_cart_updated()
+
+func _on_cart_updated():
+	for c in get_children():
+		remove_child(c)
+		c.queue_free()
+	
+	var list_entry
+	for entry in Global.cart:
+		list_entry = list_entry_scene.instantiate()
+		list_entry.entry = entry
+		add_child(list_entry)