async function injectHead(html, element) {
	const transformer = posthtml([
		tree => {
			tree.walk(node => {
				if (node.tag === 'head') {
					node.content.push('\n\t\t', element, '\n');
				}
				return node;
			});
		}
	]);
	const result = await transformer.process(html);
	return result.html;
}
@param {string} html
@param {{tag: string, attrs: Record<string, string>, content: string[]}} element
@returns