FlexBox Mixins

@include flex =display: flex +
( 1: justfy-content, 2: align-item, 3: column, 4: wrap )

don't have to fill everything, can exclude elements by inserting null mixin.scss

@include flex( )
@include flex(center)
@include flex(end)
@include flex(null, start)
@include flex(null, center)
@include flex(null, end)
@include flex(center, start)
@include flex(center, center)
@include flex(center, end)
@include flex(end, start)
@include flex(end, center)
@include flex(end, end)
@include flex(between)
@include flex(around)
@include flex(evenly)
@include flex(null, baseline)
@include flex(null, stretch)
@include flex(null, null, column)
@include flex(null, start, column)
@include flex(null, center, column)
@include flex(null, end, column)
@include flex(null, null, reverse)

if alot =>

@include flex( )
@include flex(null, null, column)
@include flex(null, null, null, wrap)
@include flex(null, null, null, reverse)
@include flex(null, null, column, wrap)
@include flex(null, null, reverse, reverse)