Add tabulate and ruff dependencies

pyproject.toml

@@ -1,4 +1,11 @@
 [project]
 name = "matrixmania"
 version = "0.1.0"
-dependencies = ["tabulate", "ruff"]
+dependencies = ["tabulate", "ruff"]
+
+[project.optional-dependencies]
+dev = ["pytest", "ruff", "pytest-cov"]
+
+[tool.pytest.ini_options]
+pythonpath = ["src"]
+testpaths = ["test"]