add login/sign-up page with dark/light mode

node_modules/has-flag/index.js

@@ -0,0 +1,8 @@
+'use strict';
+
+module.exports = (flag, argv = process.argv) => {
+	const prefix = flag.startsWith('-') ? '' : (flag.length === 1 ? '-' : '--');
+	const position = argv.indexOf(prefix + flag);
+	const terminatorPosition = argv.indexOf('--');
+	return position !== -1 && (terminatorPosition === -1 || position < terminatorPosition);
+};