add all frontend files

node_modules/eslint/lib/rules/utils/unicode/is-emoji-modifier.js

@@ -0,0 +1,13 @@
+/**
+ * @author Toru Nagashima <https://github.com/mysticatea>
+ */
+"use strict";
+
+/**
+ * Check whether a given character is an emoji modifier.
+ * @param {number} code The character code to check.
+ * @returns {boolean} `true` if the character is an emoji modifier.
+ */
+module.exports = function isEmojiModifier(code) {
+    return code >= 0x1F3FB && code <= 0x1F3FF;
+};