Add description to card metadata

This metric implements the evaluation harness for the HumanEval problem solving dataset
described in the paper "Evaluating Large Language Models Trained on Code"
(https://arxiv.org/abs/2107.03374).

README.md

@@ -1,6 +1,6 @@
 ---
 title: Code Eval
-emoji: 🤗 
+emoji: 🤗
 colorFrom: blue
 colorTo: red
 sdk: gradio
@@ -8,10 +8,16 @@ sdk_version: 3.0.2
 app_file: app.py
 pinned: false
 tags:
-- evaluate
-- metric
----
+  - evaluate
+  - metric
+description: >-
+  This metric implements the evaluation harness for the HumanEval problem
+  solving dataset
+
+  described in the paper "Evaluating Large Language Models Trained on Code"
 
+  (https://arxiv.org/abs/2107.03374).
+---
 # Metric Card for Code Eval
 
 ## Metric description