Doc: Define example install paths in .qdocconf

QDoc needs to know the directory under which the examples are
installed in QT_INSTALL_EXAMPLES. Without them, example manifest files
may contain invalid paths.

Change-Id: I3d27517e41e3b1deb7643ca1a40f3905c0e5cc1a
Reviewed-by: Martin Smith <martin.smith@digia.com>

src/multimedia/doc/qtmultimedia.qdocconf

@@ -32,6 +32,9 @@ qhp.QtMultimedia.subprojects.qmltypes.sortPages = true
 exampledirs += ../../../examples/multimedia \
                snippets
 
+# Specify example install dir under QT_INSTALL_EXAMPLES
+examplesinstallpath = multimedia
+
 headerdirs += ../..
 
 imagedirs += src/images \

src/multimediawidgets/doc/qtmultimediawidgets.qdocconf

@@ -28,6 +28,9 @@ qhp.QtMultimediaWidgets.subprojects.classes.sortPages = true
 exampledirs += ../../../examples/multimediawidgets \
                snippets
 
+# Specify example install dir under QT_INSTALL_EXAMPLES
+examplesinstallpath = multimediawidgets
+
 headerdirs += ../
 
 imagedirs += \