Add callback to additional features

[charlesLoder]

Additional features option, should be able to take a string or a callback function

ADDITIONAL_FEATURES: [{
    FEATURE: "word",
    HEBREW: "הָאָֽרֶץ",
    TRANSLITERATION: (word) => { /** do something here* / }
  }]

The callback type definition would have to change depending on the FEATURE selected.

Additionally, the HEBREW property already gets converted to a regex, so a regex should be allowed too

[johnlockejrr]

Good idea! This should bypass the exceptional cases like שְׁתַּיִם (that was exceptionally consonantal cluster in Proto Semitic also). Is this implemmented globally or by transcription "tradition" (SBL, Brill etc.)?