Update metrics metadata

README.md

@@ -19,7 +19,10 @@ model-index:
     dataset:
       name: Common Voice 8
       type: mozilla-foundation/common_voice_8_0
-      args: en
+      config: en
+      split: test
+      args: 
+        language: en
     metrics:
     - name: Test WER
       type: wer