Add artifact input to action.yml + improve logging

action.yml

@@ -3,6 +3,9 @@ description: |
   Displays test results directly in GitHub. Supports .NET (xUnit, NUnit, MSTest), Dart, Flutter and JavaScript (JEST).
 author: Michal Dorner <dorner.michal@gmail.com>
 inputs:
+  artifact:
+    description: Name or regex of artifact containing test results
+    required: false
   name:
     description: Name of the check run
     required: true