async function append(parent, child) {
	const tree = getTree(Object.values(filesTree), parent);
	if (!tree || !tree.children) return;

	const childTree = await Tree.create(child);
	tree.children.push(childTree);
	getAllFiles(childTree);
	emit("add-file", childTree);
}
Add a file to the list
@param {string} parent file directory
@param {string} child file url