Fix typo in fetchmore example documentation

In fetchmore example documentation there's a typo on the first line.
The text should read 'shows how to' but instead reads 'shows how two'

Change-Id: Ifc169581e8fc43315dc01c7d1f267dd45600af82
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@qt.io>

examples/widgets/doc/src/fetchmore.qdoc

@@ -29,7 +29,7 @@
     \example itemviews/fetchmore
     \title Fetch More Example
     \ingroup examples-itemviews
-    \brief The Fetch More example shows how two add items to an item view
+    \brief The Fetch More example shows how to add items to an item view
     model on demand.
 
     \image fetchmore-example.png