add usage metric

Author: vincentezw

action.yml

@@ -43,6 +43,11 @@ outputs:
 runs:
   using: 'composite'
   steps:
+    - name: Track usage
+      run: |
+        metric='{"name": "oxygenctl-action.usage", "type": "count", "value": 1}'
+        curl -X POST -H "Content-Type: application/json" -d "$metric" https://metrics.myshopify.dev
+
     - name: Build and Publish to Oxygen
       shell: 'bash'
       id: 'oxygen-cli-action'