in file grid.less need symbol '&'

[Konev Rodion]

In the file grid.less, for example, class .center without & means element with .center class descended from an element with class .@{css-prefix}.row (.fish.row).

<div class='fish row'>
   <div class='center'>
    </div>
</div>

In the file Row.vie we have

<div class='fish row center'>
<div>

Two doted selector without separation .name1.name2 (&.center)
means element that has both class name1 and name2 eg: class="name1 name2".

You need fix to

  &.start {
    .justify-content(flex-start);
  }
  &.end {
    .justify-content(flex-end);
  }
  &.center {
    .justify-content(center);
  }
  &.space-around {
    .justify-content(space-around);
  }
  &.space-between {
    .justify-content(space-between);
  }