Update syntax.md
Update syntax.md

Fixed a tiny problem
bookiza/docs,bookiza/docs,ProcessOut/documentation,kasko/docs,Ibercheck/api-docs,Ibercheck/api-docs,claylo/api-docs,linchpinio/docs,ProcessOut/documentation,claylo/api-docs,bookiza/docs,Ibercheck/api-docs,ProcessOut/documentation,linchpinio/docs,linchpinio/docs,bookiza/docs,claylo/api-docs