Added eslint configurations, and jquery.

src/frontend/static/script/.eslintrc.yml

@@ -0,0 +1,22 @@
+env:
+  browser: true
+  es2021: true
+  jquery: true
+extends: eslint:recommended
+overrides: []
+parserOptions:
+  ecmaVersion: latest
+  sourceType: module
+rules:
+  indent:
+    - error
+    - 2
+  linebreak-style:
+    - error
+    - unix
+  quotes:
+    - error
+    - double
+  semi:
+    - error
+    - always

src/frontend/static/script/bulma-helper.js

@@ -0,0 +1,6 @@
+$(document).ready(function() {
+  $(".navbar-burger").click(function(){
+    $(".navbar-burger").toggleClass("is-active");
+    $(".navbar-menu").toggleClass("is-active");
+  });
+});