Doc: use standard wording in \brief commands

QDoc does some magic with the \class and \namespaces
and \brief commands, so the following wording must be used:
"The xxx class yyy ..."

Change-Id: Id231f30e8464898b776888d5423523de404aae34
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

src/libs/utils/headerviewstretcher.cpp

@@ -37,7 +37,8 @@ using namespace Utils;
 /*!
     \class Utils::HeaderViewStretcher
 
-    \brief The class fixes QHeaderView to resize all columns to contents, except one
+    \brief The HeaderViewStretcher class fixes QHeaderView to resize all
+    columns to contents, except one
     stretching column.
 
     As opposed to standard QTreeWidget, all columns are