Bug fixes and improvements (#1318)

* Sync zh and zh-hant versions

* Update en/README.md

* Add a Q&A for chapter of introduction

* Update the callout headers

* Sync zh ang zh-hant versions

* Bug fixes

docs/chapter_stack_and_queue/deque.md

@@ -27,28 +27,28 @@
     from collections import deque
 
     # 初始化双向队列
-    deque: deque[int] = deque()
+    deq: deque[int] = deque()
 
     # 元素入队
-    deque.append(2)      # 添加至队尾
-    deque.append(5)
-    deque.append(4)
-    deque.appendleft(3)  # 添加至队首
-    deque.appendleft(1)
+    deq.append(2)      # 添加至队尾
+    deq.append(5)
+    deq.append(4)
+    deq.appendleft(3)  # 添加至队首
+    deq.appendleft(1)
 
     # 访问元素
-    front: int = deque[0]  # 队首元素
-    rear: int = deque[-1]  # 队尾元素
+    front: int = deq[0]  # 队首元素
+    rear: int = deq[-1]  # 队尾元素
 
     # 元素出队
-    pop_front: int = deque.popleft()  # 队首元素出队
-    pop_rear: int = deque.pop()       # 队尾元素出队
+    pop_front: int = deq.popleft()  # 队首元素出队
+    pop_rear: int = deq.pop()       # 队尾元素出队
 
     # 获取双向队列的长度
-    size: int = len(deque)
+    size: int = len(deq)
 
     # 判断双向队列是否为空
-    is_empty: bool = len(deque) == 0
+    is_empty: bool = len(deq) == 0
     ```
 
 === "C++"