Merge pull request #1419 from LucasXu0/fix_1413

fix: #1413 [Bug] Azrty keyboard not opening menu when typing /

frontend/app_flowy/packages/appflowy_editor/lib/src/service/shortcut_event/built_in_shortcut_events.dart

@@ -220,7 +220,7 @@ List<ShortcutEvent> builtInShortcutEvents = [
   ),
   ShortcutEvent(
     key: 'selection menu',
-    command: 'slash',
+    command: 'slash,shift+slash',
     handler: slashShortcutHandler,
   ),
   ShortcutEvent(