See the component page for updated information information.
The easiest way to install the component in your page is by using bower:
bower install p5-element
Include the component and webcomponentjs on top of you page:
<script src="bower_components/webcomponentsjs/webcomponents.js"></script> <link rel="import" href="bower_components/p5-element/p5-element.html">
Simply use html tags in your code. It will render the editor with the canvas.
Since the element encapsulates p5.js functions and runs in instance mode, you can have multiple elements in the same page and run them side by side.