Doc: Change the order of QQuickText function definitions

For Text QML type, some property and method documentation
is missing from the output because in the source file,
they appear before the '\qmltype Text' command.

This change reorders the functions so that qdoc will see
all documentation for Text QML type.

Task-number: QTBUG-35018
Change-Id: Icd995f66679d5105912ee12a7aeffd510921a54d
Reviewed-by: Martin Smith <martin.smith@digia.com>
Reviewed-by: J-P Nurmi <jpnurmi@digia.com>