Complete p5js port

[cathyatseneca]

p5js port still requires following:

• linked list - singly
• linked list - doubly
• linked list - with sentinels (doubly? singly? both?)
• queue/stack using linked lists

completing above would bring animation set to same point as processing.js version.

[catherine-leung]

• [ ] singly linked
• [ ] doubly linked
• [ ] doubly linked sentinel
• [ ] queue with LL
• [ ] stack with LL