* added addAtPosition to simple linked list
* added addAtPosition to simple linked list
* modified the add function to take an optional position command
* fixed type safety errors:
* fixed type safety errors:
* fixed type safety errors:
* fixed type safety errors:
* fixed size error
* fixed size error
* added doctest and updates the else after checking if posiiton argument less than 0 or not
* added doctest and updates the else after checking if posiiton argument less than 0 or not
* fixed the contributing.md mistake
* added doctest for out of bounds position value, both negative and positive
c9b4b8002f