Doc: Describe the qsTranslate() option (Qt Quick Designer)

Change-Id: I7033f683f86157830addf1b403baab0379f631c7
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

doc/src/qtquick/qtquick-designer.qdoc

@@ -290,6 +290,13 @@
     group. For more information about text ID based translations, see
     \l {Qt Linguist Manual: Text ID Based Translations}.
 
+    To preserve the context when editing the text or to change the context
+    by setting a binding on the text property, change the default call to
+    \c qsTranslate() by selecting the \uicontrol {qsTranslate()} radio button.
+
+    For more information, see
+    \l {Internationalization and Localization with Qt Quick}.
+
     \section2 Loading Placeholder Data
 
     \QMLD supports views, models, and delegates, so that when you add a Grid