message: WIP: add helper to center content with CSS
diff: background-size: cover;
  }
  }
  +
  +
  +/**
  + * Center child content vertically and horizontally
  + *
  + * @mixin center-content
  + * @section Layout
  + * @example
  + * @include center-content;
  + */
  +@mixin center-content {
  + align-items: center;
  + display: flex;
  + justify-content: center;
  +}
  