Add description to card metadata (#1)

- Add description to card metadata (53fe37c63e4aaf81e5d021313f5eba6adc3e893d)

README.md

@@ -1,6 +1,6 @@
 ---
 title: COMET
-emoji: 🤗 
+emoji: 🤗
 colorFrom: blue
 colorTo: red
 sdk: gradio
@@ -8,10 +8,22 @@ sdk_version: 3.0.2
 app_file: app.py
 pinned: false
 tags:
-- evaluate
-- metric
----
+  - evaluate
+  - metric
+description: >-
+  Crosslingual Optimized Metric for Evaluation of Translation (COMET) is an
+  open-source framework used to train Machine Translation metrics that achieve
+  high levels of correlation with different types of human judgments (HTER, DA's
+  or MQM).
+
+  With the release of the framework the authors also released fully trained
+  models that were used to compete in the WMT20 Metrics Shared Task achieving
+  SOTA in that years competition.
 
+
+  See the [README.md] file at https://unbabel.github.io/COMET/html/models.html
+  for more information.
+---
 # Metric Card for COMET
 
 ## Metric description