User manual ended (to be corrected?)

Proposition of style for the docs.
The export stats window have a name for the file by default.

src/statistics/Stats_window.cpp

@@ -168,8 +168,11 @@ void Stats_window::on_export_button_clicked(){
     _start_time = _start_time_widget->text().toDouble();
     _end_time   = _end_time_widget->text().toDouble();
     
+    const string &path = _core->get_filename();
+    const QString path_by_default = QString(path.substr(0, path.find_last_of('.')).c_str()) + ".svg";
+
     QString filename = QFileDialog::getSaveFileName(this, tr("Export File"),
-                                                    QString(),
+                                                    path_by_default,
                                                     tr("Images (*.svg)"));
 
     if (filename.isEmpty()) {