Add language tag

For better referencing :)

README.md

@@ -26,7 +26,11 @@ dataset_info:
     num_examples: 3003
   download_size: 3671540079
   dataset_size: 14958319130
+language:
+- fr
+- en
 ---
+
 # Dataset Card for "wmt-en-fr"
 
 [More Information needed](https://github.com/huggingface/datasets/blob/main/CONTRIBUTING.md#how-to-contribute-to-the-dataset-cards)