Problem
-Create an ADT character string linked_char by using a linked list of characters
• Main function will have a menu of options.
• Enter new string and store as linked list of characters in an ADT linked_char class
• Get current length (number of characters stored) from linked_char
• Append a linked_charto another linked_char
• Find index of character in a linked_char
• Test if a linked_charis substring of another linked_char
• Quit.