[3] Generator: Initial Path

[Thenlie]

Generate random path from start to finish ✅

A pseudo-random path is generated when the "Generate Maze" button is clicked. This renders the completed path to the front end. The code ensures that the path makes it to the finish cell. It also ensures that each yellow cell is touching exactly two other yellow cells, or the S or F cells.

I have tested maze sizes 10x10 up to 20x20 without issues. In all situations this code runs in less than one second.

NOTE: If the code fails to generate a valid path, it simply tries again. This means there could be some edge cases that take a lot of attempts to become valid. This may need to be edited in the future, or may require the maze to not increase significantly. Please open an issue if you notice this taking too long.

Closes #3

Screenshot