Fix small issue in interface documentation
Fix small issue in interface documentation

rmosolgo/graphql-ruby,nevesenin/graphql-ruby,nevesenin/graphql-ruby,xuorig/graphql-ruby,nevesenin/graphql-ruby,xuorig/graphql-ruby,rmosolgo/graphql-ruby,nevesenin/graphql-ruby,xuorig/graphql-ruby,rmosolgo/graphql-ruby,rmosolgo/graphql-ruby