Layout - main wrapper custom spacing

[chrimesdev]

What

In the NHS.UK frontend library we have some classes for custom spacing on the <main class="nhsuk-main-wrapper" id="maincontent"> wrapper to add more or less vertical spacing. Such as nhsuk-main-wrapper--l and nhsuk-main-wrapper--s however there is no guidance for this in the NHS digital service manual

Do we need to add this guidance to the Layout - Main content section

Frontend library code:

@mixin govuk-main-wrapper {
  @include nhsuk-responsive-padding(7, 'top');
  @include nhsuk-responsive-padding(7, 'bottom');
  @include top-and-bottom();
  display: block; /* [1] */
}

@mixin govuk-main-wrapper--l {
  @include nhsuk-responsive-padding(8, 'top');
}

@mixin govuk-main-wrapper--s {
  @include nhsuk-responsive-padding(5, 'bottom');
  @include nhsuk-responsive-padding(5, 'top');
}

@include govuk-exports('govuk/objects/main-wrapper') {
  .nhsuk-main-wrapper {
    @include govuk-main-wrapper;
  }
  .nhsuk-main-wrapper--l {
    @include govuk-main-wrapper--l;
  }
  .nhsuk-main-wrapper--s {
    @include govuk-main-wrapper--s;
  }
}