Fix Performance Problem.

[MarsZone]

With this code. The page performance will be huge improve. I find that, the bug is because use whole page scorll..html scroll. So that will be very very low performance.

简单来说就是干掉了html的滚动，给滚动区域加定高和滚动。这样性能就正常了。

[cnwangjie]

Thank you very much for your pr. ❤️

[MarsZone]

Add one more feature make fold all btn with expend features

[jerviscui]

有效果吗？