Generate Start and End Points
A randomly placed start and end point are generated and stored on the
board.
Handle Endpoint Collision in Board Generation
Refactor endpoint generation. The start point is in the top left corner of
the board (15%) and the end is in the bottom right (15%) corner. The
generation logic was reworked: if there is a collision between an endpoint
and an obstruction, the board is cleared and generation happens again.