New minor release

Enhancements

• Default settings (no errors if I provide nothing)
• Ability to override default settings at a test level
• Method to change folder structure (If I want all images in the same directory, for example)
• Add optional suffix to files (In case several files are in one directory, append .diff or .latest to filenames)
• Optional custom filenames
• Optional terminal prompt if screenshots differ, so user may observe differences and decide whether to override
• Improvements in the documentation
• TypeScript type definition
• Demo directory