message: fix(ContentGroup): add max-width to content copy
diff: &__title {
  @include carbon--type-style('expressive-heading-04', true);
  - @include content-width;
  margin-bottom: $carbon--spacing-07;
  }
  + &__title,
  + &__copy {
  + @include content-width;
  + }
  +
  &__copy {
  margin-bottom: $layout-04;
  