Minor rewording in tasks.md

When creating a task, the text says that the output confirms that the task completed successfully, while the task did not run yet as a TaskRun object was not created yet.

Changing the text so it imply that the task resource was created instead.

content/en/docs/Getting-started/tasks.md

@@ -131,7 +131,7 @@ running in its own container.
     kubectl apply --filename hello-world.yaml
     ```
 
-      The output confirms that the Task was completed successfully:
+      The output confirms that the Task was created successfully:
 
       ```
       task.tekton.dev/hello created