feat: add linkedlist_queue in js to doc

docs/chapter_stack_and_queue/queue.md

@@ -428,7 +428,72 @@ comments: true
 === "JavaScript"
 
     ```js title="linkedlist_queue.js"
+    class LinkedListQueue {
+        #front;
+        #rear;  // 头结点 #front ，尾结点 #rear 
+        #queSize = 0;
 
+        constructor() {
+            this.#front = null;
+            this.#rear = null;
+        }
+
+        /* 获取队列的长度 */
+        get size() {
+            return this.#queSize;
+        }
+
+        /* 判断队列是否为空 */
+        isEmpty() {
+            return this.size === 0;
+        }
+
+        /* 入队 */
+        offer(num) {
+            // 尾结点后添加 num
+            const node = new ListNode(num);
+            // 如果队列为空，则令头、尾结点都指向该结点
+            if (!this.#front) {
+                this.#front = node;
+                this.#rear = node;
+                // 如果队列不为空，则将该结点添加到尾结点后
+            } else {
+                this.#rear.next = node;
+                this.#rear = node;
+            }
+            this.#queSize++;
+        }
+
+        /* 出队 */
+        poll() {
+            const num = this.peek();
+            if (!this.#front) {
+                throw new Error("No element in queue!")
+            }
+            // 删除头结点
+            this.#front = this.#front.next;
+            this.#queSize--;
+            return num;
+        }
+
+        /* 访问队首元素 */
+        peek() {
+            if (this.size === 0)
+                throw new Error("No element in queue!");
+            return this.#front.val;
+        }
+
+        /* 将链表转化为 Array 并返回 */
+        toArray() {
+            let node = this.#front;
+            const res = new Array(this.size);
+            for (let i = 0; i < res.length; i++) {
+                res[i] = node.val;
+                node = node.next;
+            }
+            return res;
+        }
+    }
     ```
 
 === "TypeScript"