message: fix(ContentGroupHorizontal): margin size
  ### Related Ticket(s)
  Component:- ContentGroup Horizontal(Stage):- Spacing issue after heading section
  ### Description
  Added responsive margin to the Content Group Horizontal headline
  ### Changelog
  **New**
  `margin-bottom: 96px` on large and bigger breakpoint
  `margin-bottom: 64px` on other breakpoints
diff: @mixin content-group-horizontal {
  .#{$prefix}--content-group-horizontal {
  + .#{$prefix}--content-block__heading {
  + margin-bottom: $layout-05;
  + @include carbon--breakpoint('lg') {
  + margin-bottom: $layout-06;
  + }
  + }
  .#{$prefix}--content-item-horizontal__item:last-child {
  @include carbon--breakpoint('max') {
  padding-bottom: $layout-07;
  