[Fix] Kitchen Sink - iOS overscroll/bounce

[SamuelScheit]

Solve this issue: framework7io/framework7-website#491
As you can see in the video of the issue the whole website bounces and you can't scroll the inner content.
Only after you focus the inner content you can scroll it.
This can be prevented by adding this css to kitchen-sink/core/css/app.css:

html,
body {
  position: fixed;
  overflow: hidden;
}

Solution by: https://www.bram.us/2016/05/02/prevent-overscroll-bounce-in-ios-mobilesafari-pure-css/

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.