You can format the event description with HTML tags. For example:
<h2>Heading</h2>
<strong>Text in bold</strong>
<em>Text in italics</em>
<ul><li>Bulleted list item</li><li>Bulleted list item</li></ul>
Link to <a href="https://google.com">Google</a>Use the following example to embed Youtube videos.
<div class="embed-responsive embed-responsive-16by9">
<iframe src="https://www.youtube.com/embed/zpOULjyy-n8?rel=0" allowfullscreen></iframe>
</div>