Changes to spacing
Changes to spacing

- Increase spacing above contents headings
- Reduce spacing under h1
- Reduce spacing for .heading-medium on the index page

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