I have the following in my HTML:
<?!= include('Stylesheet'); ?>
include in Code.gs is:
function include(filename) {
return HtmlService.createHtmlOutputFromFile(filename)
.getContent();
}
However, when I load the page, <?!= include('Stylesheet'); ?> shows up as plain text and the CSS is not included. I feel like I am making an obvious mistake here, I have read this documentation and I just can't figure it out.