Retranslate the complete English edition from Simplified Chinese (#2010)

* Retranslate the complete English edition from Simplified Chinese

* Polish three English explanations after reader-focused review

en/codes/javascript/chapter_stack_and_queue/deque.js

@@ -4,41 +4,41 @@
  * Author: Zhuo Qinyue (1403450829@qq.com)
  */
 
-/* Driver Code */
-/* Get the length of the double-ended queue */
-// JavaScript has no built-in deque, can only use Array as deque
+/* Driver code */
+/* Initialize the deque */
+// JavaScript has no built-in deque; use an Array as a deque
 const deque = [];
 
-/* Elements enqueue */
+/* Enqueue elements */
 deque.push(2);
 deque.push(5);
 deque.push(4);
-// Note: due to array, unshift() method has O(n) time complexity
+// Note: because this uses an array, unshift() has O(n) time complexity
 deque.unshift(3);
 deque.unshift(1);
-console.log('Double-ended queue deque = ', deque);
+console.log('Deque deque = ', deque);
 
-/* Update element */
+/* Access an element */
 const peekFirst = deque[0];
 console.log('Front element peekFirst = ' + peekFirst);
 const peekLast = deque[deque.length - 1];
 console.log('Rear element peekLast = ' + peekLast);
 
-/* Element dequeue */
-// Note: due to array, shift() method has O(n) time complexity
+/* Dequeue an element */
+// Note: because this uses an array, shift() has O(n) time complexity
 const popFront = deque.shift();
 console.log(
-    'Front dequeue element popFront = ' + popFront + ', after front dequeue, deque = ' + deque
+    'Element removed from the front, popFront = ' + popFront + ', after dequeuing from the front, deque = ' + deque
 );
 const popBack = deque.pop();
 console.log(
-    'Dequeue rear element popBack = ' + popBack + ', after rear dequeue, deque = ' + deque
+    'Element removed from the rear, popBack = ' + popBack + ', after dequeuing from the rear, deque = ' + deque
 );
 
-/* Get the length of the double-ended queue */
+/* Get the deque size */
 const size = deque.length;
-console.log('Double-ended queue length size = ' + size);
+console.log('Deque size = ' + size);
 
-/* Check if the double-ended queue is empty */
+/* Check whether the deque is empty */
 const isEmpty = size === 0;
-console.log('Double-ended queue is empty = ' + isEmpty);
+console.log('Is the deque empty = ' + isEmpty);