Add codecov report

Author: jakubbogacz

.github/workflows/nodejs.yml

@@ -24,3 +24,8 @@ jobs:
         npm test
       env:
         CI: true
+    - name: Upload coverage to Codecov  
+      uses: codecov/[email protected]
+      with:
+        token: ${{secrets.CODECOV_TOKEN}}
+        file: ./coverage/clover.xml