Added Ruby phonelib third-party interface (#2873)

Co-authored-by: penmetsaa <penmetsaa@google.com>

README.md

@@ -230,6 +230,7 @@ maintenance processes.
 *   PostgreSQL in-database types: https://github.com/blm768/pg-libphonenumber
 *   Python: https://github.com/daviddrysdale/python-phonenumbers
 *   Ruby: https://github.com/ianks/mini_phone
+*   Ruby: https://github.com/daddyz/phonelib
 *   Ruby: https://github.com/mobi/telephone_number
 *   Rust: https://github.com/1aim/rust-phonenumber
 *   Erlang: https://github.com/marinakr/libphonenumber_erlang