Update buyers-guide-g-cloud.html
Update buyers-guide-g-cloud.html

update choosing a call-off contract description after feedback from nicole/zendesk.
AusDTO/dto-digitalmarketplace-buyer-frontend,AusDTO/dto-digitalmarketplace-buyer-frontend,alphagov/digitalmarketplace-buyer-frontend,AusDTO/dto-digitalmarketplace-buyer-frontend,alphagov/digitalmarketplace-buyer-frontend,alphagov/digitalmarketplace-buyer-frontend,alphagov/digitalmarketplace-buyer-frontend,AusDTO/dto-digitalmarketplace-buyer-frontend