How to add doctype html tag in BS

Suppose I have a page that I have built in BS. How do I add the <!doctype html> tag to the first line?

Many thanks.

Stupid question Andrew. Look at an exported copy of the page in an editor and confirm that BS does this automatically

Duh!

LOL well pat yourself on the back at least you worked it out hehe. Good job, keep it up! :)