Add compiler message @TODO

sources/richtext/richtexteditor.cpp

@@ -739,6 +739,7 @@ QString RichTextEditor::text(Qt::TextFormat format) const
 			break;
 #if QT_VERSION < QT_VERSION_CHECK(5, 14, 0)
 #else
+#pragma message("@TODO remove code for QT 5.14 or later")
 		case Qt::MarkdownText: //This enum value was added in Qt 5.14.
 			break;
 #endif