Add initial setup scripts and configuration for testing environment
- Created .gitmodules to include Bats testing framework and its dependencies.
- Added package.json and package-lock.json for managing Bats and its related packages.
- Implemented setup.sh for installing Homebrew and specified packages with a dry-run option.
- Introduced Bats test files to validate the setup script functionality.
- Updated .zshrc to include direnv plugin and modified local ignore settings.
- Added global .gitignore for editor-specific files and directories.