Revert "Add yet-another-react-lightbox package and update .gitignore to exclude node_modules"

This reverts commit c92f4a5edd.

frontend/node_modules/eslint/lib/shared/ast-utils.js

@@ -0,0 +1,29 @@
+/**
+ * @fileoverview Common utils for AST.
+ *
+ * This file contains only shared items for core and rules.
+ * If you make a utility for rules, please see `../rules/utils/ast-utils.js`.
+ *
+ * @author Toru Nagashima <https://github.com/mysticatea>
+ */
+"use strict";
+
+const breakableTypePattern = /^(?:(?:Do)?While|For(?:In|Of)?|Switch)Statement$/u;
+const lineBreakPattern = /\r\n|[\r\n\u2028\u2029]/u;
+const shebangPattern = /^#!([^\r\n]+)/u;
+
+/**
+ * Creates a version of the `lineBreakPattern` regex with the global flag.
+ * Global regexes are mutable, so this needs to be a function instead of a constant.
+ * @returns {RegExp} A global regular expression that matches line terminators
+ */
+function createGlobalLinebreakMatcher() {
+    return new RegExp(lineBreakPattern.source, "gu");
+}
+
+module.exports = {
+    breakableTypePattern,
+    lineBreakPattern,
+    createGlobalLinebreakMatcher,
+    shebangPattern
+};