Reword paragraph to match the order of the subsequent sections

Doc/lib/libgettext.tex

@@ -585,8 +585,8 @@ files are what the \module{gettext} module uses for the actual
 translation processing during run-time.
 
 How you use the \module{gettext} module in your code depends on
-whether you are internationalizing your entire application or a single
-module.
+whether you are internationalizing a single module or your entire application.
+The next two sections will discuss each case.
 
 \subsubsection{Localizing your module}