feat: Add ruby code - chapter "array & linked list" (#1158)

* feat: add ruby code chapter array & linked list

- array.rb
- linked_list.rb
- list.rb
- my_list.rb

* feat: add ruby code blocks

* chore: fix convention

codes/ruby/utils/list_node.rb

@@ -0,0 +1,38 @@
+=begin
+File: list_node.rb
+Created Time: 2024-03-18
+Author: Xuan Khoa Tu Nguyen (ngxktuzkai2000@gmail.com)
+=end
+
+### 链表节点类 ###
+class ListNode
+  attr_accessor :val  # 节点值
+  attr_accessor :next # 指向下一节点的引用
+
+  def initialize(val=nil, next_node=nil)
+    @val = val || 0
+    @next = next_node
+  end
+end
+
+### 将列表序列化为链表 ###
+def arr_to_linked_list(arr)
+  head = current = ListNode.new arr[0]
+
+  for i in 1...arr.length
+    current.next = ListNode.new arr[i]
+    current = current.next
+  end
+  
+  head
+end
+
+### 将链表反序列化为列表 ###
+def linked_list_to_arr(head)
+  arr = []
+
+  while head
+    arr << head.val
+    head = head.next
+  end
+end