Add evaluation results on the default config of xsum

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Your model has been evaluated on the default config of the [xsum](https://huggingface.co/datasets/xsum) dataset by @xarymast, using the predictions stored [here](https://huggingface.co/datasets/autoevaluate/autoeval-staging-eval-project-xsum-69daf1dd-12935738).\
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

@@ -1,11 +1,45 @@
 ---
 tags:
 - summarization
-
 language:
 - en
-
 license: mit
+model-index:
+- name: facebook/bart-large-xsum
+  results:
+  - task:
+      type: summarization
+      name: Summarization
+    dataset:
+      name: xsum
+      type: xsum
+      config: default
+      split: test
+    metrics:
+    - name: ROUGE-1
+      type: rouge
+      value: 45.4525
+      verified: true
+    - name: ROUGE-2
+      type: rouge
+      value: 22.3455
+      verified: true
+    - name: ROUGE-L
+      type: rouge
+      value: 37.2302
+      verified: true
+    - name: ROUGE-LSUM
+      type: rouge
+      value: 37.2323
+      verified: true
+    - name: loss
+      type: loss
+      value: 2.3128726482391357
+      verified: true
+    - name: gen_len
+      type: gen_len
+      value: 25.5435
+      verified: true
 ---
 ### Bart model finetuned on xsum