How to specify the language of the web page

Since we can't edit the html tag, is there a setting for specifying the language of the web page? My goal is to add the lang attribute to the html tag as shown below:

<html lang="en">

Ok, I just found out I can add attributes to any tag, including <html>. This can be done on the Attributes panel, which is hidden along with the HTML and CSS panels on the bottom of the editor.