init
fixed search animation
fixed remove tail animation and pseudocode
fixed all remove animation, except minor bug in remove kth
major edit to ListWidget.js to cater many vertex pointing to one vertex
fixed search and all of the remove functions
fixed all insert animation, all animations are working
added another level of dropdown for insert and remove tab
fixed insert and remove to only accept one value and fixed data validation
fixed double level menu for create insert and remove
added stack and queue operations
updated button for push and enqueue, updated layout for list,stack, and queue
added doubly linked list layout, and fixed insert head operation for doubly
added insert tail for doubly
fixed all insert for doubly list but cannot control the arrow overlap
fixed minor bug and typo
added remove head for doubly
added remove tail for doubly
updated minor colour bug in remove tail doubly
added remove kth for doubly, doubly linked list done
completed deque