Bootstrap 4: auto-suggest drop-down as in the official bootstrap site : <p>If you go to <a href="https://getbootstrap.com/docs/4.0/getting-started/introduction/" rel="noreferrer">https://getbootstrap.com/docs/4.0/getting-started/introduction/</a>, you see a auto-suggest dropdown on the left site of the official boostrap site. How do I implement the same thing on my own web pages? What library is the site using for the auto suggest? I have traced the source code but I can't find the relevant code. </p>

<p><a href="https://i.stack.imgur.com/YvNzU.png" rel="noreferrer"><img src="https://i.stack.imgur.com/YvNzU.png" alt="enter image description here"></a></p>
