title: ELM : Manage side effect
body: <p>isn't <strong>onClick</strong> <strong>(button click</strong>) a side side effect.
  in ELM language we can listen for a click event without getting hand dirty with Task and command.</p>
  
  <p>isn't a click event a <em>side effect</em> or has <em>side effect</em>, if so why we can listen to button click event without using Task</p>