add ai2d

lm_eval/tasks/ai2d/ai2d.yaml

+dataset_path: lmms-lab/ai2d
+test_split: test
+output_type: generate_until
+doc_to_image: !function utils.doc_to_image
+doc_to_text: "<image>{{question | capitalize}}
+{{% for option in options %}}
+{{loop.index | chr(64)}}.  {{option | capitalize}}
+{{% endfor %}}"
+doc_to_target: "{{options[answer]}}"
+generation_kwargs:
+  until: []
+  temperature: 0.0
+  do_sample: false
+  max_gen_toks: 512
+metric_list:
+  - metric: acc
+    aggregation: mean
+    higher_is_better: true
+metadata:
+  version: 0.0