Add description to card metadata

Precision is the fraction of correctly labeled positive examples out of all of the examples that were labeled as positive. It is computed via the equation:
Precision = TP / (TP + FP)
where TP is the True positives (i.e. the examples correctly labeled as positive) and FP is the False positive examples (i.e. the examples incorrectly labeled as positive).

README.md

@@ -1,6 +1,6 @@
 ---
 title: Precision
-emoji: 🤗 
+emoji: 🤗
 colorFrom: blue
 colorTo: red
 sdk: gradio
@@ -8,10 +8,18 @@ sdk_version: 3.0.2
 app_file: app.py
 pinned: false
 tags:
-- evaluate
-- metric
----
+  - evaluate
+  - metric
+description: >-
+  Precision is the fraction of correctly labeled positive examples out of all of
+  the examples that were labeled as positive. It is computed via the equation:
+
+  Precision = TP / (TP + FP)
 
+  where TP is the True positives (i.e. the examples correctly labeled as
+  positive) and FP is the False positive examples (i.e. the examples incorrectly
+  labeled as positive).
+---
 # Metric Card for Precision