When you're writing something using the document editor, you can add a button to your text that will take you to another site when you click on it!
To add a button, hit Enter to begin a new paragraph, then click on the button icon in the middle of the menu bar (the fourth icon from the left). Copy and paste the URL of the site you want to create a button for, then add the text you want the document to show.
For example, if you wanted to create a button that would take you to Google's homepage, you would use https://www.google.com/ for the URL and "Google" for the text. When you're finished, click OK and your button will appear in the document.