Drop support for Node 14 and add support for Node 20

• -f flag for arbitrary file inclusion in the check
• Refactored check api to unify across package managers
• Use modern Yarn internally

Add autodetect & check for Berry

Automatically detect package manager

• Excludes __fixtures__ dir from published package

• Removes many extraneous files from published package
• Expands node engines config to include majors 16 and 18

• Fix bug in cli program name after package rename
• Republish with new public repo settings

• Adds initial one-version implementation
• Supports one-version check for yarn and pnpm package managers

Initial empty release to verify release workflow