Write a C program to implement a queue (FIFO) of characters in a
one-way, circular, linked list. One way means that each node has
only one pointer, Q, (not both a rear and a front pointer), so the
program must use pointers-to-pointers. Include functions to
insert(), remove(), for use in main() where the user is prompted
"Enter "i" to insert a new element, "r" to remove an element, "q"
to quit:"