feat: nextRoman, previousRoman && map

[Zubs]

This pull request introduces new functionality for working with Roman numerals, including methods to get the next and previous Roman numeral, and to map arrays between numbers and Roman numerals. It also updates documentation and tests to cover these new features, and bumps the package version to reflect the added capabilities.

New Roman numeral utilities

• Added nextRoman and previousRoman functions to get the next and previous Roman numeral for a given input, respectively, in both src/index.ts and index.js. [1] [2]
• Added a map function to convert arrays of numbers to Roman numerals or vice versa, depending on the specified type, in both src/index.ts and index.js. [1] [2]

Documentation updates

• Updated README.md to document the new nextRoman, previousRoman, and map functions, including usage examples.

Testing improvements

• Added unit tests for nextRoman, previousRoman, and map in both TypeScript and JavaScript test suites (src/tests/index.test.ts, tests/index.test.js). [1] [2]

Package version update

• Bumped the package version from 1.2.0 to 2.0.1 in package.json to reflect the new features.