Update path_patterns for assets/ layout

dataset_info.json

@@ -195,10 +195,10 @@
     "repo_id": "amazon/ConfBench",
     "repo_type": "dataset",
     "path_patterns": {
-      "original_pdf": "{doc_id}/original.pdf",
-      "ground_truth": "{doc_id}/gt.json",
-      "metadata": "{doc_id}/metadata.json",
-      "noisy_pdf": "{doc_id}/{pipeline_name}/{pipeline_name}_noisy.pdf"
+      "original_pdf": "assets/{doc_id}/original.pdf",
+      "ground_truth": "assets/{doc_id}/gt.json",
+      "metadata": "assets/{doc_id}/metadata.json",
+      "noisy_pdf": "assets/{doc_id}/{pipeline_name}/{pipeline_name}_noisy.pdf"
     }
   },
   "source": {