Main feature:
- Added functionality to randomly generate a maze before the solver
solves it.
Fixes:
- Add a public method in the Cell class called wall_exists() that
returns true if a given cell wall exists (false otherwise).
Refactors:
- Added an enum type called CellWallLabel for labelling the four cell
walls.
- Added a draw() function in the CellWall class to reduce repeated code.
- Move the custom exceptions to errors.py
Tests:
- Add tests for the custom exceptions.
CI:
- Added a workflow for Forgejo Actions.
- Raise CellInvalidError when attempting to specify the wrong corners of
the cell when creating it. The x and y values should always represent
the top left and bottom right corners of the cell.
- Raise CellTooSmallError when attempting to specify a cell which is too
small to correctly draw its central point.
- Add an entrance and exit to the maze. The entrance will always
be on the top left and the exit will always be on the bottom
right.
- Add a simple GitHub actions workflow to run the Python tests.
