add shortcuts for menu items

main.py

@@ -53,9 +53,11 @@ class MainWindow(QMainWindow):
         file_menu = QMenu(self.tr("&File", "name of the file menu"), self)
 
         open_file = QAction(self.tr("&Open..."), self)
+        open_file.setShortcut('Ctrl+O')
         open_file.triggered.connect(self._open_file_dialog)
 
         close_action = QAction(self.tr("E&xit", "menu item to close the application"), self)
+        close_action.setShortcut('Ctrl+X')
         close_action.triggered.connect(self.destruct)
 
         self._update_recent_files_menu()
@@ -68,6 +70,7 @@ class MainWindow(QMainWindow):
     def highlight_menu(self) -> QMenu:
         result = QMenu(self.tr("&Highlighting"), self)
         manage = QAction(self.tr("&Manage"), self)
+        manage.setShortcut('Ctrl+M')
         manage.triggered.connect(lambda: HighlightingDialog(self.settings).exec())
         result.addAction(manage)
         return result