Distinguish text content from HTML content

In templates, is there any way to distinguish plain text content from HTML content? Or does the caller need to always escape arbitrary text values?

As a contrived example, in the docs under the "Event" header, if I type <b>bold! into the text box, bold text appears, so it seems I can insert arbitrary HTML. That's fine for hard-coded values, but seems like a security issue for anything derived from user input.

For what it's worth, I like the minimal, modern JS-based approach of ArrowJS, but this seems like a potential footgun :)