Add GitHub Repo

I saw all the leaderboards are in the GitHub repo already, why not redirect the readers to it instead?
Also, readers know what PCA-Bench is after clicking on this linkage.

app.py

@@ -3,5 +3,5 @@ import gradio as gr
 def greet(name):
     return "Hello " + name + "!!"
 
-iface = gr.Interface(fn=greet, inputs="text", outputs="text", description="Online Leaderboard 👉： https://docs.qq.com/sheet/DVUd4WUpGRHRqUnNV")
+iface = gr.Interface(fn=greet, inputs="text", outputs="text", description="GitHub Repository 👉： https://github.com/pkunlp-icler/PCA-EVAL")
 iface.launch()