wip: add more questions

src/data/question-groups/javascript/content/immutable-object.md

@@ -0,0 +1,12 @@
+To make an object immutable, you can use `Object.freeze()` method. It prevents the modification of existing property values and prevents the addition of new properties.
+
+```js
+const roadmap = {
+  name: 'JavaScript',
+};
+
+Object.freeze(roadmap);
+
+roadmap.name = 'JavaScript Roadmap'; // throws an error in strict mode
+console.log(roadmap.name); // JavaScript
+```

src/data/question-groups/javascript/javascript.md

@@ -206,4 +206,9 @@ questions:
     topics:
       - 'Core'
       - 'Advanced'
+  - question: How to make an Object immutable in JavaScript?
+    answer: immutable-object.md
+    topics:
+      - 'Core'
+      - 'Advanced'
 ---