Update README.md

README.md

@@ -70,7 +70,7 @@ The file structure is as following:
 ├── metadata-validation.parquet
 └── metadata-test.parquet
 ```
-The sub-folders have the name of <split_name>_<part_id>, and the JSON file have the same name as the sub-folder.
+The sub-folders have the name of {split_name}_{part_id}, and the JSON file have the same name as the sub-folder.
 Each image is a lossless WebP file, and has a unique name generated by [UUID](https://en.wikipedia.org/wiki/Universally_unique_identifier).
 
 ### Data Instances