title: How can I rewrite my root directory pages url to directory
body: <p>I have below urls in my website
  <a href="http://www.abcdef.com/about.php" rel="nofollow noreferrer">http://www.abcdef.com/about.php</a>
  <a href="http://www.abcdef.com/contact.php" rel="nofollow noreferrer">http://www.abcdef.com/contact.php</a></p>
  
  <p>I want to change the address URL look as below 
  <a href="http://www.abcdef.com/about-us/" rel="nofollow noreferrer">http://www.abcdef.com/about-us/</a><br>
  <a href="http://www.abcdef.com/contact-us/" rel="nofollow noreferrer">http://www.abcdef.com/contact-us/</a></p>
  
  <p>How can n achieve this without making new directories? How can I rewrite the URL, what Rewrite rule should I write? </p>