uni-app加载时渐隐淡入效果

由于组件加载成功后，突然显示出来比较生硬，所以需要对其进行动画修饰。

.load-list{
  opacity: 1;
  animation-name: list;
  animation-duration: 2s;
  animation-timing-function: linear;
  animation-direction: alternate;
}

@keyframes list{
    from{ opacity: 0 }
    to{ opacity: 1 }
}