Update README.md

README.md

@@ -15,7 +15,7 @@ configs:
 - config_name: cube_easy
   data_files: cube_easy.parquet
 - config_name: portal_binary
-  data_file: portal_binary.parquet
+  data_files: portal_binary.parquet
 - config_name: portal_blanks
   data_files: portal_blanks.parquet
 ---