feat: Implement Sudoku game with grid generation, validation, and solving features

- Added Sudoku grid generation with varying difficulty levels (easy, medium, hard).
- Implemented Sudoku solving functionality.
- Created a user interface for inputting and checking Sudoku solutions.
- Added validation for user inputs and error handling for invalid grids.
- Introduced a Docker configuration for easy deployment.

.gitignore

@@ -30,6 +30,9 @@ yarn-debug.log*
 yarn-error.log*
 .pnpm-debug.log*
 
+# local editor settings (can contain infrastructure credentials)
+.vscode/
+
 # env files (can opt-in for committing if needed)
 .env*