Add justfile for common development tasks

[kjaymiller]

Summary

This PR adds a justfile to streamline common development tasks for the Black Python Devs website. The justfile provides convenient command recipes that wrap common operations using uv for package management.

Available Recipes

• just install - Install project dependencies using uv
• just serve - Run the development server with live reload
• just build - Build the static site for production
• just test - Run the test suite with pytest
• just lint - Check code quality with ruff
• just format - Format code with ruff
• just pre-commit-run - Run all pre-commit hooks
• just clean - Remove build artifacts and cache directories
• just dev - Full development setup (install + pre-commit + serve)

Usage

After installing just, you can run any recipe:

just build
just test
just dev

Run just without arguments to see all available recipes.

Benefits

• Consistent command interface across the project
• All commands properly use uv for package management
• Simplifies onboarding for new contributors
• Reduces need to remember specific command syntax

🤖 Generated with Claude Code