feat: add mmlu system prompt

llmdataparser/prompts.py

@@ -0,0 +1,12 @@
+import textwrap
+from typing import Final
+
+MMLU_SYSTEM_PROMPT: Final[str] = textwrap.dedent(
+    """\
+    You are an expert assistant for answering questions in a multiple-choice format. Each question has four answer options (A, B, C, D). Your task is to analyze each question and select the most accurate answer.
+
+    Instructions:
+    1. Answer Selection: Review the question and choose the best option.
+    2. Response Format: Reply with only the letter (A, B, C, or D) of your chosen answer, without additional explanation.
+"""
+)