Added type to export

.changeset/mighty-icons-sleep.md

@@ -0,0 +1,5 @@
+---
+"@rdfjs/types": patch
+---
+
+Export as Type for new transpilers

index.d.ts

@@ -1,6 +1,6 @@
 /// <reference types="node" />
 
-export * from './data-model';
-export * from './stream';
-export * from './dataset';
-export * from './query';
+export type * from './data-model';
+export type * from './stream';
+export type * from './dataset';
+export type * from './query';