Fix model-index metadata (add dataset fields)

README.md

@@ -22,6 +22,9 @@ model-index:
   - task:
       type: text-classification
       name: Clustering
+    dataset:
+      type: mjbommar/ogbert-v1-mlm
+      name: OGBert v1 MLM Eval
     metrics:
     - type: adjusted_rand_index
       value: 0.7302
@@ -29,6 +32,9 @@ model-index:
   - task:
       type: retrieval
       name: Definition Retrieval
+    dataset:
+      type: mjbommar/ogbert-v1-mlm
+      name: OGBert v1 MLM Eval
     metrics:
     - type: mrr
       value: 0.9596