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

node_modules/es-abstract/2019/thisStringValue.js

@@ -0,0 +1,13 @@
+'use strict';
+
+var $StringValueOf = require('call-bound')('String.prototype.valueOf');
+
+// https://262.ecma-international.org/6.0/#sec-properties-of-the-string-prototype-object
+
+module.exports = function thisStringValue(value) {
+	if (typeof value === 'string') {
+		return value;
+	}
+
+	return $StringValueOf(value);
+};