intro vign now downloads flights data, closes #3102 (#3271)
intro vign now downloads flights data, closes #3102 (#3271)


jangorecki/data.table,vlulla/data.table,jangorecki/data.table,Rdatatable/data.table,vlulla/data.table,Rdatatable/data.table,Rdatatable/data.table,vlulla/data.table,jangorecki/data.table,jangorecki/data.table,vlulla/data.table,Rdatatable/data.table