title: Validating userName using Regex
body: <ol>
  <li><p>The only numbers in the username have to be at the end. There can be zero or more of them at the end.</p></li>
  <li><p>Username letters can be lowercase and uppercase.</p></li>
  <li><p>Usernames have to be at least two characters long. A two-letter username can only use alphabet letter characters.</p></li>
  </ol>
  
  <p>I'm trying with this but I'm stalled. <code>/\d+$\w+/gi
  </code></p>