feat: Add Python dependency management and fix test environment

- Add install-pip.sh script for automated Python package installation
- Add pyproject.toml with proper package configuration and setuptools discovery
- Fix virtual environment setup to enable all tests to run successfully
- Tests now pass: 20/20 ✅

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

pyproject.toml

@@ -0,0 +1,15 @@
+[build-system]
+requires = ["setuptools>=61.0"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "markitect"
+version = "0.1.0"
+description = "Advanced Markdown engine for structured content"
+readme = "README.md"
+requires-python = ">=3.8"
+dependencies = ["markdown-it-py"]
+
+[tool.setuptools.packages.find]
+include = ["markitect*"]
+exclude = ["tests*", "wiki*", "tddai*"]