Decrease the spacing underneath headings on the index page
Decrease the spacing underneath headings on the index page

These sit too far away from the content underneath, reduce the
whitespace to make it clear that the summary content relates to the
link above.

TFOH/govuk_elements,alphagov/govuk_elements,gavboulton/govuk_elements,joelanman/govuk_elements,gavboulton/govuk_elements,TFOH/govuk_elements,alphagov/govuk_elements,gavboulton/govuk_elements,alphagov/govuk_elements,gavboulton/govuk_elements,alphagov/govuk_elements,joelanman/govuk_elements