NOTE: the latest version is 2.0.0
@docs Spacing, toCss, px3, px6, px9, px12, px18, px24, px30, px36, px42, px54, px72, px90, px120, px180, i3xs, i2xs, xs, sm, md, lg, xl, i2xl, i3xl, i4xl, i5xl, i6xl, i7xl, i8xl