Added import and export for the level designer

ExportPanel.gd

@@ -0,0 +1,15 @@
+extends PanelContainer
+
+func _ready() -> void:
+	pass
+
+func show_panel(ob : Dictionary) -> void:
+	var text = JSON.stringify(ob, "  ")
+	var b64 = Marshalls.utf8_to_base64(text)
+	$VBoxContainer/ExportedCode.text = b64
+	visible = true
+	$VBoxContainer/ExportedCode.select_all()
+	$VBoxContainer/ExportedCode.copy()
+
+func _on_close_pressed() -> void:
+	visible = false