Document the default value for QAbstractItemView::editTriggers

Change-Id: I4456dcfcecf739299533167867208e1943bc4a26
Reviewed-by: Christian Ehrlicher <ch.ehrlicher@gmx.de>
Reviewed-by: Thorbjørn Lund Martsum <tmartsum@gmail.com>
(cherry picked from commit 408959c8c85badfcd374b21fb2e6071c40e5cba4)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

src/widgets/itemviews/qabstractitemview.cpp

@@ -1263,6 +1263,12 @@ void QAbstractItemView::doItemsLayout()
     \l{EditTrigger}, combined using the OR
     operator. The view will only initiate the editing of an item if the
     action performed is set in this property.
+
+    The default value is:
+    \list
+    \li for QTableView: DoubleClicked|AnyKeyPressed
+    \li for all other views: DoubleClicked|EditKeyPressed
+    \endlist
 */
 void QAbstractItemView::setEditTriggers(EditTriggers actions)
 {