fix(docs): add missing await to pagination example (#1190)

README.md

@@ -467,7 +467,7 @@ for (const fineTuningJob of page.data) {
 
 // Convenience methods are provided for manually paginating:
 while (page.hasNextPage()) {
-  page = page.getNextPage();
+  page = await page.getNextPage();
   // ...
 }
 ```