Basic Link-list Data Structure

Basic link-list data structure I've done as part of odin project.

The following is the non-exhaustive list of functionalities ( they're implemented as properties and methods of LinkList class ):

• append(value) - adds a new node containing value to the end of the list
• prepend(value) - adds a new node containing value to the start of the list
• size - returns the total number of nodes in the list
• head - returns the first node in the list
• tail - returns the last node in the list
• at(index) - returns the node at the given index
• pop() - removes the last node from the list
• contains(value) - returns true if the passed in value is in the list and otherwise returns false.
• find(value) - returns the index of the node containing value, or null if not found.
• toString() - represents linkList objects as strings, so you can print them out and preview them in the console. The output format is: ( value ) -> ( value ) -> ( value ) -> null