fix: 缩短short_description以符合HuggingFace要求

README.md

@@ -7,7 +7,7 @@ sdk: gradio
 app_file: app.py
 pinned: true
 license: apache-2.0
-short_description: SAGE - A High-Difficulty, Multidisciplinary Benchmark for Frontier Scientific Reasoning
+short_description: SAGE Scientific Reasoning Benchmark Leaderboard
 sdk_version: 5.43.1
 tags:
 - leaderboard