opt: video subtitle

avoid refetching subtitle
fix stuck when parsing large subtitle body

opt: viewpoints

Update README.md

Signed-off-by: bggRGjQaUbCoE <githubaccount56556@proton.me>

lib/pages/setting/extra_setting.dart

@@ -1,3 +1,5 @@
+import 'dart:math';
+
 import 'package:PiliPalaX/pages/main/controller.dart';
 import 'package:PiliPalaX/pages/member/new/controller.dart'
     show MemberTabType, MemberTabTypeExt;
@@ -212,6 +214,15 @@ class _ExtraSettingState extends State<ExtraSetting> {
               GlobalData().grpcReply = value;
             },
           ),
+          SetSwitchItem(
+            title: '显示视频分段信息',
+            leading: Transform.rotate(
+              angle: pi / 2,
+              child: Icon(Icons.reorder),
+            ),
+            setKey: SettingBoxKey.showViewPoints,
+            defaultVal: true,
+          ),
           Obx(
             () => ListTile(
               enableFeedback: true,