extensions/github-authentication/src/authServer.ts/sendFile
function sendFile(res: http.ServerResponse, filepath: string) {
	fs.readFile(filepath, (err, body) => {
		if (err) {
			console.error(err);
			res.writeHead(404);
			res.end();
		} else {
			res.writeHead(200, {
				'content-length': body.length,
			});
			res.end(body);
		}
	});
}