[Aaqibhafeezkhan]

Summary

• Add validatePlate and isValidPlate with Romanian county-code lookup.
• Normalize lowercase input and ignore spaces, dots, and dashes.
• Return the normalized plate, county code, and county name in data.
• Cover county plates, Bucharest's 2- and 3-digit forms, normalization, and invalid input with tests.
• Update the public exports, README API examples, and Unreleased changelog.

Format source

The Romanian Government's road-traffic regulation, HG 1391/2006, Article 23, defines the registration number as the county or Bucharest indicator, a numeric serial, and three uppercase Latin letters:
https://legislatie.just.ro/Public/DetaliiDocument/264861

Closes #9.

[Aaqibhafeezkhan]

reviewed the validator, public exports, county lookup, input normalization, and valid and invalid plate test cases.