Update README.md

lm_eval/tasks/gsm8k/README.md

@@ -31,6 +31,18 @@ Homepage: https://github.com/openai/grade-school-math
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 ```
 
+### Subtasks
+
+- `gsm8k_yaml`
+- `gsm8k_cot`: GSM8K with Chain-of-Thought
+- `gsm8k_cot_self_consistency`: GSM8K with Chain-of-Thought and Self-Consistency
+
+### Groups
+
+- `greedy_until`
+- `math_word_problems`
+- `chain_of_thought`
+- `self_consistency`
 
 ### Checklist