Add evaluation results on the default config and test split of xsum

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Your model has been evaluated on the default config and test split of the [xsum](https://huggingface.co./datasets/xsum) dataset by

@morenolq

, using the predictions stored [here](https://huggingface.co./datasets/autoevaluate/autoeval-eval-xsum-default-ca7304-1504954794).\
Accept this pull request to see the results displayed on the [Hub leaderboard](https://huggingface.co./spaces/autoevaluate/leaderboards?dataset=xsum).\
Evaluate your model on more datasets [here](https://huggingface.co./spaces/autoevaluate/model-evaluator?dataset=xsum).

README.md

@@ -5,10 +5,45 @@ tags:
 - summarization
 model-index:
 - name: bart-base-xsum
-  results: []
+  results:
+  - task:
+      type: summarization
+      name: Summarization
+    dataset:
+      name: xsum
+      type: xsum
+      config: default
+      split: test
+    metrics:
+    - name: ROUGE-1
+      type: rouge
+      value: 38.643
+      verified: true
+    - name: ROUGE-2
+      type: rouge
+      value: 17.7546
+      verified: true
+    - name: ROUGE-L
+      type: rouge
+      value: 32.2114
+      verified: true
+    - name: ROUGE-LSUM
+      type: rouge
+      value: 32.2207
+      verified: true
+    - name: loss
+      type: loss
+      value: 1.8224396705627441
+      verified: true
+    - name: gen_len
+      type: gen_len
+      value: 19.7028
+      verified: true
   dataset:
-      type: {xsum}
-      name: {xsum}
+    type:
+      xsum: null
+    name:
+      xsum: null
 ---
 
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