I have a Visualforce page, used in the Sites, that I've been asked to add the Google tag manager to.
I have one block of script that comes with the instruction to "embed the following Javascript code before the close tag of the header"
I have another code block that's an iframe wrapped in a block. that is supposed to go "after the opening body tag".
How can I place these blocks when "header" and "body" are not Visualforce tags?
This answer suggests making an empty html5 container page, but I need content in my page: